At any age you are, there is a difference between the age you feel and the age your peers look to you.
If you dont spend time around a variety of people you are unlikely to readjust your mental image of what the age you feel looks like.
How many new people do you spend time with on a regular basis.
How do you spend your time?
When we are younger we are constantly put into a situation where you are surrounded by people your own age that you see every week multiple times(typically school and other group based hobbies like sports) but also people who are 1 to 5 years your junior and senior who you may not talk with much but they are still a part of what you encounter all the time.
As you get older this environment shifts. Post highschool students start to see their classmates diversify in age. They are still your peers but age isnt no longer (as much) the defining factor of who you will engage with and work with, but its usually not suddenly all your classmates are now more than a few years older or younger than you.
This starts to expand but also stunt your change in what your perceptionnof what you see around you and who you see as a reflection of what people your age look like.
And those who dont continue education are typically just entering a workforce and now have a lot less people like them around them. Age at work places are much more varied, but its also different depending on the field you work in.
Life starts to get weird in your 20s because its not the same as your experience of the people you see as your own age(among other things).
But we also typically have stopped growing taller by this point. Which i think adds a lot.
So when you as a 20 something now start getting to know people who could be or almost be your parents you have been trained to recognize age as a qualifier, and at 14 you probably should see age as a good indicator of people who are likely to be people you can relate to.
Its easier to see differences than similarities. They jump out at you. Like boiling a frog you dont know that things are changing so you dont react the same way as if you are suddenly hit with it.
Of course this isnt everyones experience, but it does happen enough that its worth giving some thought to.