Sometimes enough is enough because of the failures comes to us that makes worst our lives so we can say that's enough.We can't blame enough because failures will bring us to nothing which is very hard to survive.
Well, this depends on what is happening and what are you doing in your life. You must pass something if you know that nothing is happening to it even if you are doing your best. I know that there are these sayings like don't stop, keep in believing but it depends on what you really are doing like gambling. If you are an investor, don't stop, keep on learning and doing things but if you are a gambler, you must think carefully since gambling can ruin lives, not only your life but other else's life too.