So in the end, yes, it is still greed that brings and directs them to regret because they lose all their previous winnings again, so the conclusion is there is no other way than to be firm and disciplined in the planning that we have previously made.
Greediness is one of the common denominators of gamblers.
We hate it but we have to admit that we've got this common attitude towards gambling and in investments too. That's why even with so much winnings when greed comes, the profit that is already guaranteed can be taken away with a single bad decision.