Im about the person and sharing their perceptions. I like people i can learn from in a positive way. Their age/gender are about "packaging" not who the person is. Too much emphasis is put on what we look like. It should be who we are.

I like a person’s personality. If that’s a ten year old or a seventy year old, I am happy to be their friend.

I disagree with 1) and 2). My own experience tells against the assertions.

I don't know other people who hold those views, but maybe it's because of the people I tend to befriend (clearly there is reciprocal thinking).

Because of my lack of knowing people with such views, I can't be sure as to whether certain groups have a higher propensity.

I think that mentality is akin to the whole "keeping to your own" train of thought. It is just by design to keep people separated to cause division. It all ties together: racism, ageism, ableism, political parties, etc. It is all designed to keep us away from the only true realization and that is we are all HUMANS and we need each other. Just my thought.

Your mother was probably trying to protect you from unwanted sexual exploitation. But, overall, her advice was bad. A number of my best and enduring friends have been women and I never tried to hit on any of them. Also what matters in friendship is not age, but intelligence, shared interests and values, and ability to open and honest with each other.

Update to the first one: two ppl of matching sexual orientation can't be friends as adults?

On the second one, definitely not true. I basically view an age difference like a cultural difference, when it's within the same culture.