My first thought was a quote, I think it was by Thomas Edison? "I have not failed, I have just found 10 000 ways that won't work".

Anyway... failure... I think the trick is not to keep going on an idea or to try it once and then say "ok, it didn't work", but to look at that idea and say "ok, it didn't work that time, what can I do to amend this original idea or what other way can I get around this problem?"

Occasionally you realise that the original idea you had cannot happen or will not happen in its current incarnation. It is only a complete failure if a person gives up entirely.

I get the feeling it is life you are talking about though... and not all of us have the strength to look for a Plan B, especially when trying to get Plan A to work has been like flogging a dead horse, pardon the expression. I think that finding the mindset to say "ok, my plans haven't worked, what can I do now?" and then following it through is probably the first step to recovery.