At 20, there's often this feeling that if you can find your slot, start adulting, life will shift into easy mode. Things will be simple and straightforward once that is established. 

That this is not true is pretty much impossible to explain, and if you try, it sounds like you are saying "no, life sucks forever, trust me", which isn't the point. It's absolutely true that I prefer being nearly 50 to being 20 and that my life is better. But what got better wasn't that I got married and had a kid and didn't have to worry about dating any more and so things were simple. It's more like my mental and emotional capacity to handle the complexity grew. But trying telling a 20 year old their mental ans emotional capacity is still immature.