I'm 31 and feel like I'm beyond milestones. I'm at the age where society tends to expect me to have reached certain markers of "true" adulthood. The marriage, house, real career, kids ideal that most people have of a capitol 'A' adult. I haven't hit any of those. Some because I don't want them. Some because I procrastinate. Others because I spent all of my 20s making very little money and saving none of it.
I never gave any thought to what I'd be like as an adult when I was a kid. Mostly I just wanted to get away from the little nuts I went to grade school with. Then, since most of them followed me to high school, I just wanted to graduate. When I was in college all I could think about was getting out of school once and for all. I gave no honest thought to post-collegiate plans. Not where I would live, who I would date, or how I would dress. Not even where I would work. I wanted to move on, but had no idea to what.
I was seriously depressed and unmedicated through most of my pre-teen to early adult years. All I ever envisioned for my future was one where I was finally happy. I thought that if by some miracle I could sustain some joy in living that everything else would fall into place. So I made no plans, held out no hopes. Just in case happy never came.
My catch-22? I'm mostly happy now (thank you Effexor), but the plans I failed to make all those years ago are haunting me. I have $5,000 in credit card debit, no savings, a job I hate, interest in an industry that's hellishly hard to break into, a paycheck that barely covers my bills, an interest in buying a house next year without much real hope of making it happen and fear coming out of my ass like water.
Once you become a real live grown-up the only milestones left are the ones you create on your own timetable. That's one of the cool things about finally being one of "the big people". The crappy thing is that nobody is obligated to make decisions on your behalf. Primary equation: adulthood=it's all your fault.