I think it depends where you are at with your game, what level you play, cash or tournies.
I started to read poker books
because I wanted to learn how to choose when to play certain cards, such as when you fold 84 and the flop is Q44. I thought there was a game theory to when to do this. What I learnt was cards that I thought were good, K9 in particular, were in fact trash. So I learnt hand selection.
Then I realised I was very passive, hated preflop raising, so I slowly brought this into my game and now it's second nature. And so it continues.
What I think is important to realise is that when you try a new technique it might fail the first 3 times and so you drop it. However if you had tried it 20 times it might work 13-14 times.
Keep at it, and if you feel your own plays work for you then carry on. Figure out what part of your game needs work e.g. do you call too much, bet sizing etc, and see what they have to say in the books about it.