As the title asks, when did you first realize that you were genuinely getting older? Maybe have more aches and such, got crows feet, a wrinkle here or there, or just looked/felt older than you ever remember?
Still young at 70. Feeling old is a state of mind, not body.
After I got married it started to get hard to stand up after crouching. Incidentally it was probably all the physical over work I was doing at the time.
when you start looking more forward than backward. Thinking about what you need vs what you want. when i started making every decision myself. started buying my own furniture, even kitchen appliances, without even thinking of consulting my parents in the decision process. I started learning what I REALLY liked. Also when my friends started getting married and buying houses. That will really open your eyes!
Depends how you frame the question. Personally, I felt like an adult when I got my first apartment lease without a co-signee. As for feeling "old", give me a few dozen years.
When you can't fit in the McDonalds playplace anymore.
After I got married it started to get hard to stand up after crouching. Incidentally it was probably all the physical over work I was doing at the time.