Let's be honest here: being an adult is nothing to get excited about. Seriously, remember when you were younger and you thought reaching adulthood would be the very peak of your existence? Well, we're here now, and all I can say is, it's a snooze fest.
In my experience, being a grownup means spending an absurd amount of time planning meals (you're responsible for making all of those now), researching why your leg might hurt (you'll never know), and going to bed before 10 PM (the same bedtime you had when you were in middle school).
If you're also feeling a little letdown by the boring realities of adulthood, I think you're really going to relate to these quotes.