I'd like to refer Doyle Brunson quote -Poker is war. People pretend it is a game.
I believe this is the philosophy of all gamblers, you sit play to win, nothing else. I doubt some people when I see them saying - I play for fun, I love game only etc. Certainly poker is complex and perfect game, it's even addiction for most people. But if you play with your money in it, you won't be there only for fun. Sometimes philosophy is simple - I'll lie if I have big hands or absolute nothing doesn't matter, I'll take your money.
Understanding the game takes lot of experience.
Also, it's teachable at some aspects.