What really, really helps for me is to go and explain the problem to some other programmer, preferably not a perl programmer. Mostly I get the solution halfway my explanation.

And no this isn't abstract or vague, but a real-world question, actually. Somebody else already hinted to 'Zen and the art of motorcycle maintenance' from Robert Pirsig. Great book, worth a read. It touches this thread on 'the state of mind', you could say.<P.Cheers,

Jeroen
"We are not alone"(FZ)