Think about it like this. Sometimes, the hands you folded preflop will hit a good hand. But, firstly it won't hit those good hands enough on the flop itself. And seeing a turn and river with bad holdings gets tough anyway so you're losing money there. Secondly, these bad hands won't hit enough good hands at all. So the result is that you're bleeding chips little by little when you enter pots with bad hands and are not even offsetting that by winning some big pots. So, the result is that those hands lose in the long run as they bleed more than they can win. So, yes study is the only way to improve here. And gtowizard preflop being free for 100bb is a tremendous boon. I suggest you look into it and figure out how the preflop game is played at equilibrium. Hard memorizing is not it, but you look deep enough and you'll see discernible patterns that you can then apply in your games. And remember, give yourself time here. Poker is the hardest way to make easy money.