A book will give you the mechanics, but you must have a feel for the game. Yes, experience and talent. It is not a feeling like you may have in other areas. It is an understanding, an insight that the other player is bluffing, for example. A good player that you have played with only once three years ago, if something important has happened between you and him, he will remember that.
Some players have that talent within themselves.
You see people who have never played bridge or bowled and right from the start, some will play better than others. They don't know the game at all, but show them the basics and one will play a lot better than the other. Poker can't be different from that. Some players with the same amount of experience and who have read the same books will achieve a higher level because of their natural talent. Others will pay a Cadillac to get their experience and still will not know how to play any better.