I have a similar experience with hitting both ends of the execution-perfection spectrum. When launching a new product\project I would spend loads of time on inconsequential details, slowing my progress, as you said it really is just procrastination\avoidance; sometimes lazy people keep themselves very busy with the wrong things. There is a book I ready yearly, "Ready Fire Aim" by Michael Masterson. It awakened me to some of the things slowing me down. I also ask myself regularly throughout the day "Is this what I should be doing right now?"