There have been a couple times when I climbed out of my comfort zone and into "no retreat" situations, either because of soloing or trying to make a new route go, and once because of not having the right piece of gear for the pitch. In all of these cases I have eventually been in a situation where I have made moves I was uncertain of success on, where the consequence for failure was death or life-changing injury. I couldn't recommend these pitches to anyone, and I would have to say that nowadays at least I would do a lot to avoid them, but I'm as proud of having succeeded on those pitches as I am of anything else I have ever done, because if I hadn't I would not be here.