Many of the top players have other forms of income beside's Poker, some might have properties they let out for rent, or they could be joint owners in other businesses, sharing the profits, or even buying businesses outright and pay a manager to run them, there are many ways to make a living from Poker winnings.
The important thing is they have diversity, and do not "Put all their eggs in one basket" They don't risk all their money in one career, Many top Businessmen and Women Poker players still play as an amateur player, because their businesses pay them a Living and they can afford to play Poker at the highest level, but as a hobby, and there is nothing wrong in doing that.
The most important thing to remember, is whichever way you approach it, Poker is a game, a gamble, and as long as you can afford to lose the buy-in, without it taking food from your Children's mouth's, or risking the roof over their heads, then you should play as much as you want, but would you want to play everyday? Being able to have the choice whether to play or not to play, makes Poker so much more than a career, and a lot more FUN!
When the fun Stops, STOP!
Main, infinite patience 
