I think Greed is only the big mistake in gambling.
Well greed is the most known thing that let people make mistakes because they get addicted to gambling because of that.
Yes totally agree with you.
yes, sinking into greed when gambling, is a fatal mistake. it can affect the long term. could have it, makes you have a lot of debt, because they want to win the stakes in gambling with a great gift.
You won't be in a lot of debt if you manage your resources. If you lose something that you can afford then it's okay. If you go beyond that, like selling your watch, cellphone, car, etc. You probably are addicted and want to get back what you lost, probably that's what's going to happen if you do that. Be careful and smart when gambling.