Don't put all your available bankroll directly in the game (in case you're using deposits). Leave always at least half outside as a security measure if you go bust.
What will you do with the other half if you bust? Would you come next day(or any other day) to gamble with it? If you have 100$ which you can afford to lose, why would you take only half of it? It is EV- game, separating funds doesn't make much sense in long run.
I think, he just wanted to tell that it isn't necessary to spend all money for gamble.
All these tips has already been discussed and keeps on discussing in one way or another but the matter of fact is that none of them will work until someone have a strong self control.
Probably most of people has problems with self control therefore gamblings are forbidden in some countries, so such threads with elementary texts are necessary.