It's a lot easier than you think. When I was a kid I wrote longer programs in Basic using paper and pencil, because it was a lot easier for me than typing. I would type in the program after I was pretty sure it was right. The errors were almost always local. It seemed so easy to check the high-level structure of something when I could spread it out on the ground in front of me. Later, in college, I always printed out drafts of my papers and marked them up completely before I started editing.