Good advice! You should be ready to win as well as to spend the money you wanted to double, however, there shouldn't be hard feelings, as the main reason why you gamble in the first place (in my opinion, of course), is the thrill of it. It's not like that spent money is going to be the end of the world, but it's sometimes seen like that.
Those who think like that (the end of the world) when their money has run out in gambling are people who have no preparation whatsoever in gambling, including their mentality and also special capital for it. Because people who enjoy the thrill in any gambling will not be so concerned about losing and running out of money because it is money that is deliberately prepared for that so those like that will never be upset and panic when facing defeat in gambling.