In general I agree, things seem to go by faster as I have gotten older. But I also have a little more wisdom (I hope) and try not to speed through things. Mindfulness helps a lot. I want to remember savoring my meals and cuddling my pup and feeling exhilarated listening to a favorite piece of music. It's not easy taming the monkey mind but worth the work, I'm finding.

Sure, as my life shortens, times gets shorter...and much faster. It will in your life too - if you live that long. lol

Yes... I'm getting older. I had an eventual life before age 65. I don't have much time left. Have some fun.

OK. Personal theory only based on another personal theory, so read "absolute bunkum -probably"
When you are a year old, the year ahead represents an additional 100% of your life coming up. When you are 5, it represents another 20% coming up. Think back to 5, how long was a school year? lifetimes, how long between Xmasses? Time does not exist in the mind, you can recall something from 5 years ago or 10 minutes ago.
When you go somewhere for the first time, it stands alone, it isn't attached to other memories. Maybe the same if you make the same trip a few times. So you walk down a road every day for a few years. Your mind does not remember each trip, it remembers the road, walking down it and that you have done it many times. The repetitive memories are strengthens like making a deeper groove as opposed to numerous grooves, but in addition, you remember the time you found $20, the time the dog bit you and so on. Extra bits that get added as a tag along to the main memory of walking down the road more than a few times.
So it is with your memory of your life, instead of just one year or 5 years of memories, I have almost 60 years of them, they are compressed, and last year is only less then a 2% addition to my previous memories, many of which are only repetitions of previous experiences, to the additional remembrances do not add as much to the store as a years worth previously. And as time means nothing to the mind, a weeks memory can flash through it in an instant, five minutes can be considered to 1/2 an hour. But there are some tricks, I believe that a well functioning brain does not forget, it just sometimes has trouble remembering. You go to introduce one friend to another but "forget" their name so you don't. 5 minutes later you remember their name, you hadn't forgotten it, you simply failed to recall it. Practicing recall is awesome learn your triggers. I cheat, I am hyperthymesic, my trade off for lack of emotional intelligence I guess.

Seems to me age is proportional to speed the time flies bye. Currently 45 km/hr XD

Seems to be speeding up all the time ! Flying by !

And in the past, I only heard this from older folks. But it seems to me, that since 9/11, I've heard this from people of all ages. Perhaps we all got a clear glimpse of our mortality then ...

time is relative - and I don't really mean in the Einsteinium way.

yes I remember visualizing the breakdown of time in a day when I was about 8. the day was about as far ahead as I looked
. Ditto on what felt like long Christmas vacations summers and such. We won't talk about the length of a Sunday Service

The explanation I have read is that when you are young, that 3 month to Christmas is a large segment of your life, your awareness. When you are older it become a smaller percentage, say at 60 it's 1/240 of your awareness, a much shorter span.

Yes it does change dramatically. I've read different theories, most of which get too clinical for my mind, but I think it's just because a given unit of time, say, a day, is an increasingly smaller percentage of your total experience.

You are so right. Time is precious. I don't know why perception of time changes as years pass.