I can see what he's getting at - programming involves building up a mental picture of everything that's going on in your program. Of course most professional pr

I can see what he's getting at - programming involves building up a mental picture of everything that's going on in your program. Of course most professional programmers probably don't work on a single project for months that's all theirs, they have to work with modules/interfaces developed by other people - when you don't have the luxury of writing all the code yourself (even terrible programmers know what's going on in their own spaghetti), being able to comprehend complex systems in a few hours is a huge advantage. They might still write terrible code if they were never taught good practices, but at least it does show ability/potential.