For some reason, I have always been sensitive about my age, but not for the reason you may expect: I've always been upset that I'm so young.
As a teenager, I was upset at being a teenager. You can't pick your age, you know, and it wasn't my fault I was at an age that happened to end in the suffix -teen. I never did classify myself as a teenager either, even though I did do some stupid teenager things and even though I did sometimes make disparaging remarks about teenagers.
I like to consider that we are all part of the human race, and since we don't get to pick how old we are, what does it matter? We can choose to act however old we want. I'm watching a 10-year-old this week, and after just one morning with her she commented that I seemed more like her sister than her mom. That's because I don't stick to all the stupid rules that so many adults follow: I vowed as a child to never be that stuffy adult who looks down her nose at children.
That said, I don't actually believe in "old" either. You are only as old as you make yourself. If you want to be old at 21, you can be old. If you want to be old at 55, you can be old. For me, I think old may start somewhere around 87. And even then I'm not sure--ask me in 61 years.
My cousin and I once started making a list to determine our real "age" as defined by our habits and tastes. We were each trying to prove to the other that we were older (I'm older). I can't remember what we said exactly, but here are some possible examples:
1. Go to bed before 10 pm on a regular basis: add 10 years to your age
2. Take a vitamin: +5 years
3. Have a savings account that you add to regularly: +3
4. Own or rent a house/apartment/condo by yourself: +5
5. Have kids: +5
6. Eat a balanced diet: +5
7. Read the newspaper: +2
8. Do the crossword: +1
9. Knit, crochet, quilt, sew, embroider, etc.: +3 years
10. Don't watch tv: +5 years
You could add a bunch more, of course.
By these calculations, I am not 26 years old, but 35. Okay, maybe that's a bad example because 35 is not that old. How my cousin and I had it I got a much better score, like 45 or something. But you get the idea.
In conclusion: I cannot help that I am 26. You cannot help how old you are either. In the grand scheme of things we may all be the same age anyway, and 10 or 20 earth years is not such a big difference.