I know that spiders like to try, try, try again. They're famous for it. I saw one yesterday though that really shouldn't have bothered and also clearly wasn't paying attention at spider persistence school because it eventually realised that too.
It was amazingly trying to build a web between the ceiling of a train carriage (where it had a nice little hideaway in a ventilation duct) and the top corner of a commuter's newspaper - that he was reading! I missed how the spider managed to make it onto the newspaper in the first place, but it had managed to attach some sort of webby anchor point. Of course, every time the commuter turned the page the poor spider was flung off into space, being saved only by its silken safety harness. It kept climbing back up only to be repeatedly launched across the carriage. The commuter was completely oblivious the drama occurring on the other side of his paper. After about 20 minutes the spider eventually gave up and beat an undignified retreat back up to its ventilatory hideaway.
You've got to admire its optimism though, imagine looking down on a carriage full of people and thinking "You know what, that flapping newspaper looks like an ideal place to anchor my web." No I can't imagine that either, not because I'm not a spider and so neither live in ventilation ducts nor spin webs (although I don't) but because spiders presumably don't think in any way you or I would recognise. But you get the point.
