As I ponder many things, I think of Robert Vaughn's character in "The Magnificent Seven" and Doc's epitaph to Johnny Ringo: "Poor soul, he was just too high-strung," and come to how it is OK to be scared, but if the plan is sound, the key is to go ahead anyway--even if you're scared.
I was feeling pretty smug and wise for distilling this Great Truth--until I realized it is literally the ending of "The Wizard of Oz."