How does that story about the hammer go? This guy wants to hang a few pictures, but he has no hammer. He knows the neighbor has one. On his way over to borrow it, he starts thinking. What if the neighbor is not home? ... What if he *is* home, but it's not a good time to disturb him? ... What if he'd rather not lend his tools to someone else? You know, come to think of it, I get the feeling he doesn't like me anyway. Wasn't he looking at me funny the other day? And the way he was washing and waxing his car last weekend - I bet he is really fussy about all his stuff. Yeah, he'd probably be all snooty about it and behave like a total prick if I asked to lend his hammer. Lecture me about it too, I bet. I'd never hear the end of it.
He bangs on the door, and when the neighbor opens, he yells at him, "I didn't want your stupid hammer anyway!"
I did something similar. Didn't get to banging on the neighbor's door, but by the time I had gotten to where I was going, I had convinced myself it was a really bad idea to stop by. Just stupid. Wouldn't work anyway. I stopped at a coffee shop two blocks from my destination, drank a cup of coffee, read another chapter of "The Heart Is A Lonely Hunter", turned it over in my mind some more - and then I turned right around and went back home.