Having a great idea and have it crash and burn

I don’t mean this in the sense of trying to bring a dream into fruition.  I mean this in the sense that you have a fantastic idea and you are about ready to start implementing it and for some reason you just shut it down completely and start thinking of other options / ideas.

Physical fitness is too unknowable

Every body is different, and it’s incredibly difficult to find the right system that will work for you. And even if you do, your body will eventually build a resistance to that diet or workout regimen, rendering it useless.

I want the previously mentioned nanobots to tell me what the best workout, sleep and nutrition combinations will get me to my physic goals. I’m still happy to put in the work, I just need direction catered to my unique body

Being a peace keeper

If ever given the circumstance to be a peace keeper, you know it socks being stuck on the middle.  Is there a one line phrase that can be said, regardless of the situation that calms any situation?