The second you turn 18 years old, the rest of the world expects you to act like an adult (except for your parents, who will pretty much always see you as a baby just learning to walk). You get all kinds of crazy responsibilities and privileges that you didn't have before, and you're not really even sure what all of them even are.

Despite the legality of your adulthood, it usually takes a while to sink in. Here are a few things that really, truly make you feel like you're actually old enough (and responsible enough) to vote.

1. Having more than three digits in your savings account.

And not counting the numbers after the decimal point, either. This not only makes you feel grown up and responsible, but also like you never want to buy anything again in your life so it never goes back to what it was before. *shudders*

2. Paying for your own stuff.

And I don't mean your own clothes or gas. I'm talking about real life stuff -- the deposit for your dream study abroad trip, the down payment on a car (and subsequent car payments), those really expensive boots you've been drooling over for a year, or the dress you have to wear for your best friend's wedding in eight months.

3. The second your best friend since diapers gets engaged.

Even if you knew it was coming, it's still going to be a shock. A wonderful, beautiful shock which you'll squeal about into the phone no matter where you are.

4. ... and calls you to ask you to be her MOH before she remembers to tell you she's engaged.

And trust me, you'll remember exactly where you are when you get this phone call (McDonald's, just outside of Richmond). And you'll never let her forget that, either.

5. Flying somewhere for the first time without "adult supervision."

Flying at any time is fun, but especially when you're not with your parents (no offense, guys). The flight attendants treat you like an adult because you're acting like an adult -- plus, drinking Sprite out of a plastic cup on a plane where you're not related to anyone just makes you feel so classy.

6. Buying groceries that aren't just ice cream, chips or soda.

When you start making health-conscious decisions about what you're putting into your body, and using your own money to buy the stuff you now want to eat instead of having your mom force-feed it to you, you'll wonder where time went (and then add in a tub of cookie dough for good measure).

7. Feeling accomplished when you go to bed before midnight.

We all love sleep, but two years ago you felt like a grandma for going to bed before midnight. Now, you feel like the coolest kid on the planet (and it makes all of your friends jealous).

8. When you start voluntarily waking up before 10 a.m.

While I don't think this will ever be fun or easy, getting up earlier to get stuff done and have more time in a day is something I finally understand.

9. Having the same pet peeves as your mom.

All those times she yelled at you for not emptying the dishwasher or for leaving dirty dishes in the sink? Yeah, she was right. She always is.

10. Shaking your head in worry for the generation right behind you.

You sound like the grouchy old man in a rocking chair on his front porch yelling at the kids to get off his lawn. But they really do seem that bad.

Happy adulting!