The faith timeframe

What defining moment makes you say 'ok, enough is enough' or has you believe that faith and hope is dwindling and starting to resemble a level of unrealistic expectation? As natural optimists (I like to believe that naturally we are optimists and that in life certain things turn us into pessimists - and not the other way round) I think that we honestly continue to have faith in anything, any person or any situation until such time that something or someone  else distracts us from this into realising that we needn't limit ourselves to only one faith, hope or dream, we can have many, and that if one dream isn't realised - then we can dust ourselves off and pursue another. For so many people in so many situations it is at least a healthy alternative to just never knowing when enough is enough and trying and failing each time with a repeated scenario. I only had to witness this a few times with people I know, to see that we are all the same in this. It's hard to surrender to an outcome we weren't hoping to surrender to, yet the sooner we did, the sooner we'd adapt and the sooner we'd find comfort and happiness even in what you have or will come to have. It also doesn't have to be the end of the world if we don't always get what we want out of life, because humans by nature are ambitious and by having this inbred characteristic - always desire things beyond our means. Well, not necessarily 'beyond' our means. But something that definitely requires work and effort to attain. I guess, the point is when you know you've exhausted your work and effort, sometimes you need to realise that that particular 'need' or 'want' is something that you're going to have to surrender to as being a different outcome that you had originally hoped.