It isnt hard. All the problems are in your head. You are right. When the right one comes, you just know. However, a lot of people are confused. They care about what one girl thinks, and care about why she dosent want to be with them, instead of spending their time finding ones that do. Now, granted we all want a super fine ass btich, but that only lasts so long. Eventually you need something more than just sex. If all you want is sex, then power to you, that is easy to get too.
One thing to remember though, back when parents were your age, things were different. There were social pressures to settle down and get married, and have 1.5 kids. You want to know why the divorce rate is so high? It is all these couples who just settled for what they had, and then realised down the road that that dosent work. Look at the huge numer of single 40+ year olds.
Basically, the first thing to overcome is to stop caring what girls think about you. This one dosent like you? All right, fine. Fcuk her, go get another one, her loss. A lot of these guys here on this board have a problem with letting them go. They are not rare commodities here, it's about 50/50 in the world, so that's like what, 4 billion chicks? Half of which are legal age, and half of that that are hot. So that leaves....ummmm....1 billion chicks? Now all you have to do is find one that likes you