The easiest things are that you get to do whatever you want!
You can wander around nekkid in your home, decorate how you want, you can take long, hot showers without worrying about someone waiting for the bathroom or using up all the hot water, and you have all the freedom that comes with making the rules in your own place. Also, no one else will eat your food, wear your clothes, or "borrow" something without your permission.
The hardest part, for me, is that I am the one who is responsible for fixing things, killing spiders, paying the bills, and making sure the house is presentable for guests. I never had to worry about any of that before I moved into my own place.
The first time the toilet wouldn't stop running, or the pilot light went out on the water heater, I had to figure out how to fix it! Now, I can fix most routine problems in the house, killing bugs is no big deal (but I still make a show of it for guys

), I am much better at managing my finances, and I usually keep the house (mostly) clean.