In my (microlight) training, which took several years and several instructors, I was repeatedly told to ALWAYS HAVE A PLAN B. I have always stuck to that rule and it has served me well.
That same rule keeps me from crossing the English Channel flying: disallowed to climb higher than 6500', I'd have several minutes where the only plan B would be to ditch and hope for the best. However sorry I am to miss the challenges of UK airspace, I'm staying put this side.
<sarcasm>But of course I am flying a flimsy microlight, powered by the notoriously unreliable Rotax 912 ... </sarcasm>