Define 'Old'

This is me and my grandparents earlier this year around my grandma's birthday. She just turned 68!!

I'm 24. In fact, I forgot how old I was the other day and said I was 23. Not because I want to be younger, but I honestly keep forgetting how old I am! It's kind of weird.

I have about 3 friends (maybe even more) who have been FREAKING OUT over their 25th birthdays. Why? Because that's so oooollllddddd. One friend even said it's because that's half-way to 50 and the other said that she was having her 'quarter-life crisis.'

What defines 'old'?

I've always felt that old is a feeling. My mom has always said that she doesn't care about her age and she looks like she's in her 30's (I swear! She's 47). And my grandparents still take my grandma's Miata and drink martinis and just have fun and go on adventures. I guess it's because no one acts their age in my family that we all feel like we always have, no matter the number you put on it.

My husband's family, though, is different. Everyone there is very old, no matter their number. And I think that's because they worry. A LOT. Over everything. Some of it, I can understand. Some of it, I cannot. So we just don't tell them when we're going bungee jumping or going to do other insanely stupid things.

I don't know if I understand my friends when they say that 25 is so OLD. The only thing that has ever made me feel 'old' is my younger brother. He's now my height and I still remember when he was to my knees and we would run around together.

So now I'm somewhat curious. What do you think defines being 'old'?