Honestly how quickly I forget about a loss depends on how invested I was in the outcome, which is probably the case for the majority of people. There's some losses in life I'll think about every now and then in a "life would have been quite different" way but they never dominate my thoughts so I think I'm doing quite alright.
It is when you want to hold on to them that you will end up losing more, because the mindset of recovering the money is what will be on your mind. Because losing money is annoying, so the best thing is to spend what you can afford to lose so that even when you don't win, you won't have things to worry about because people need to know that if they don't win today, then they will win another day, and this is one of the best decisions that can help them better because who would have expected to ponder about losing money? So just bet what is affordable to lose. And when you look or talk about it too much and you don't gamble with a specific prize, you will just end up betting and losing instead of having your wins be more than your losses.