What's something that's made you feel like a grown-up?

A lot of memes I across the Internet are about how everyone, no matter how old, is just a kid inside, trying to figure out what's going on, which is something I definitely identify with.

But every once in a while, something happens that does actually make me feel like a grown-up. It's usually small, and kind of silly, but it's fun, and I thought people might want to share theirs.

For me, most recently, it was realizing I like Greek yogurt now. It was trendy when I was like 12, and I couldn't stand it then, but I bought some on a whim, and now I keep the fridge stocked. That drastic change in my tastes took me aback momentarily, but I thought it was a nice fun little milestone.

How about you?