Correct, and the number one mistake some gamblers make which leads to their loss even before they start gambling is not materializing their funds. The second one is strategy which is something you have also pointed out, the third is knowing the game that works for them (mine is playing the slot game that always gives me a high chance of winning), and the last one is knowing when to walk away which is withdrawing of fund.
I think that all this is like the stages that one as a player has, first you have to see many possibilities of playing, how you will play and what refers to the strategy, second play what you have more chance of winning, or better the favorite game and what one as a player believes you have more chance of winning, already having defined that it is preferable to say I am going to spend only this amount x of money and I am not going to go overboard, and what I am going to play is game X, when I play slots what I do is bet the minimum and very little in general, although they are the game that pays the most it is also somewhat difficult to win.