Self growth. It's what happens in your 20s. You are constantly learning new things about yourself; what you like, what you don't like, what you need from your relationships with your parents, friends, and significant others. You're learning what makes you happy, and you finally feel like you can make the decision on what you actually want to do with the rest of your life.
Your 20s are your time to be selfish. So, be freakin' selfish. By selfish, I don't mean to throw your care for others out the window. Rather, do things that make YOU happy, and that are going to bring purpose to your life for the long run. Do things that are crazy (But not too crazy, not encouraging you to break the law or anything!) Do things to help yourself and to help those around you. Discover what makes you feel alive and do that.
Life is too short to not do the things that you want to do, especially when you are young. I think too many people in their early 20s are ready to settle down super quick and want to skip out on experiencing life. Now, it's all fine and dandy to aspire to marriage and kids, and to want that for your future self. But I know for me, personally, I don't want to wake up at 40 years old and say "Where has the time gone? I haven't experienced anything."
So, don't settle for the mediocre job that you don't really like just because it pays well. Choose the job that requires you to be bold, that takes you out of your comfort zone, that makes you do things that you might not normally do. Test yourself and let life take you places that you're scared of going. Work and save money to go on that trip you have always dreamed about. Text that person that you've always been interested in and ask them out. Try the new hobby that you've always wanted to be good at.
If I have learned anything in my short 20 years of life, it's that you have to do the things that scare you sometimes. You have to take risks. You have to work hard for what you really want. You have to let go of relationships and friendships that aren't rewarding. You have to follow your heart instead of following your head. You have to make decisions based off of what you think is right for YOU, despite what you have been told.
Don't wake up one day realizing that you have never lived in the here and now. The time is NOW to do the things you want to do, to get rid of the people that don't support you, to learn the new things that have always inspired you, and to go after the goals that you can't seem to let go of.
Stop being content with mediocrity. Go for the gold and make sure you are in relentless pursuit for it.