My birthday is today (Friday). Turning 37 is not very spectacular, but after it pasts I'll be closer to 40 than to 35/mid-thirties.
I'm not afraid of turning 40 because of the age. "You're over the hill" can suck it, I don't care. It's more about my accomplishments or lack thereof. One thing I recommend not doing is comparing yourself to your parents. "When my dad was my age, he was blah and had already blah blah blah with two kids and blah..." It's depressing. Don't do it. (Unless your parents were fuck-ups, then go for it.)
Most people my age have a family, a primary care physician that is checking their prostate on a regular basis and a job that has them looking ahead towards possible retirement. I've just started an entry-level job that is part time. I've moved into a room in a house of a couple I know...I'm doing a lot of things that are very 19-to-22ish. But you know...not everyone gets a chance like this to start again. I'm very fortunate. It takes being without certain things everyone takes for granted for a few months to really appreciate your own space...your own bed...your privacy.
We'll see what happens in the next year...Happy birthday to me.