In my opinion, it depends on how those changes came about. Life events that are brought about due to one's personal experiences can and should make a person evolve/grow/develop into a better human being. How you perceive things is usually connected to your attitude. If a person changes interests and beliefs to please those around them, it's called acting.

It is not really possible to change "everything" about yourself. Certainly you can change superficial things-your interests, styles, beliefs. People do that all the time, some more than others. But we can't really change our genetics, experiences growing up, deeper elements of our personality.

But you are a process, not a thing. Every cell in your body changes every 7 years. Our perceptions of our experiences change with age. Our body & mind can change profoundly as we age. If we develop dementia like Alzheimer's, we may forget our previous self & lose cognizance of all our previous relationships.

So what is the self? As Heraclitus said, "You can't step in the same river twice". You are not the same person you were yesterday, or even 10 seconds ago. Actually you are many selves depending on context--parent, child, spouse, employee, etc.

The key idea here is pattern. Let’s suppose—I’m going to borrow a metaphor from Buckminster Fuller—suppose we have a rope, and one section of this rope is made of manila hemp, the next section is cotton, the next section is silk, the next section is nylon, and so on. Now we tie a knot in this rope—just an ordinary one-over knot—and you find, by putting your finger in the knot, you can move it all the way down the rope. Now as this knot travels, it’s first of all made of manila hemp, it’s then made of cotton, it’s then made of silk, it’s then made of nylon, and so on. But the knot keeps going on. That’s the integrity of pattern; the continuing pattern, which is what you are. Because you might, you know, be—for several years—you might be a vegetarian, and you might be a meat-eater, and so on. And, you know, your constitution changes all the time, but your friends still recognize you because you’re still putting on the same show. It’s the same pattern that is the recognizable individual.

Alan Watts

... yes? ... no?
People change and evolve their feelings and thoughts all the time ... we are always becoming new people!
That being said, we are also born with a particular genetic code and a particular brain chemistry and biology that set the foundation for who we are.
... so sure we might change our beliefs, interests, and feelings over time and change and evolve ... but we are always still built on and from that foundation we are born with.

We are always who we are. There is technically no such thing as yesterday. There is only the now.

Interesting question.... Perhaps we can cut this one seven ways from Sunday

Yeah, I don't think you can say they're the same person. Not in a meta sense. They're still A person, but to anyone that knew them, they're definitely a DIFFERENT peson

That's a really simple question with no easy answer. Really it just depends on your priorities and definitions.

For example, you could look at any object moving in a straight line through space and argue that because it no longer has access to the past, it can not be the same object, constantly and continuously transforming its position.

That's not a very pragmatic solution, because we can assume the object has the same properties at different locations. But if the object is going through some sort of physical transformation as it moves, then the lines become blurry. Certain properties can be expected to stay the same without external influence, such as mass, charge, or spin. So, if all of these things are predictable then we can apply the assumed physical transformation to the object and discern that it is the same.

If there is external influence on the object, that's when things get complicated. Now new objects are coming in to replace old parts, and external forces are changing the transformation of the object in ways that may be hard to predict. But the question is weather or not the metaphysical person is the same, so ultimately it will come down to how useful it is to consider that person who has changed the same.

For property or government concerns, it is obvious that they are the same, because if we assumed that anyone who changed their interests is a different person, we would never get anywhere as a society. For interpersonal levels, it may be useful to consider someone different if they violate your trust in some way and you can no longer be friends with them. People change, and your relationship changes with them and with your own changes. What's important isn't if they are changing or not, it's how those changes are effecting themselves and the world.

I have changed interests, style, beliefs and many other things in my life, but I am sure I'm still the same person...

We can not completely efface what we are or what made us who we are. Even in rejection, we are influenced by what we have been.

Only these are defined a person....?? I don't think so

I don't think so. Every person will change because we are learning and growing everyday. As it is said - Change is constant.

That person remains that person, yet they are different. Same person, different traits.

Do you believe or live exactly like you did 5, 10, 15 years ago, or as a child? Do you still wear the same clothes, listen to the songs you liked back then, the same books over and over again? So what if this person changed faster than you. They are still a human being. Life changes us all.

One more thing.

This question evokes the continuous versus discontinuous ways of seeing the world.
Because in the question you skip the process, let's say when you are half changed, are you the same person as before the change? are you the same as after the change?
break this stages more and more, until you have a continuous process.
Even if you define that the beginning and the end are not the same, when is the border between them?

The answer is: The border does not exists by itself, it is an arbitrary choice, depends the definition that you give.

The same happen with species and evolution, you can't pinpoint the generation where a new species is born, you can only name stages and the border itself is not clear, and it won't as it is not something that exists by itself.

Our brain is not used to think into continuous things.

Another example: Someone is hetero or homosexual.
I would say that strictly hetero is as uncommon as strictly homo, they are the limits of a continuous line, but culture society and the labeling itself forces us into this discontinuous categories.

The person is the same, because even if everything changes, is because the past experiences brought the need/will to change.

"What is better - to be born good, or to overcome your evil nature through great effort?"
―Paarthurnax[src]

This sentence shows that past is not erased, but you can change, and the effort and learning that you need to put into changing are even more valuable than to those who gets something "naturally"

Any change has to come from within. And it's not about wiping out who you are, because that's impossible. It's taking what you have and transforming it gradually, reshaping how you see yourself and the world, while at the same time altering the way you act and interact. Otherwise, it's just a mechanical superficial shift which really doesn't change anything about who you are.

Semantics. We all change. As our population increases, (158 more births, than deaths, per minute) our rate of change increases.

Alvin Toffler in "Future Shock" said this increased rate of change is the result of population density; The more crowded it is....the more people you meet....the more subject you are to different opinions, styles, tastes, attitudes.

[en.wikipedia.org]

[organism.earth]

To be honest, I have to say both yes, and no.
Although yes, over the years I have changed the way I think, the way I treat others, the way, well the list goes on and on. However there is still that little boy frightened and full of nightmares that will always have a part of my psyche. But also in that little boy also has the curiosity of Science, Space, Math, and a great deal of other positive things.
Some things I love about myself, I really have to fight to retain, as well as the bad things I have to fight to keep at bay.
I guess the only real change is how I deal with both. That has really changed over the years.

no. read steppenwolf, by hermann hesse.

g

Yes but still the core person is the same compassion, character etc

I'm not who I was yesterday, and yesterday is gone!

Ship of Theseus

[en.m.wikipedia.org]