Visions

Eyes work using a page fault mechanism. They’re so good at it that you don’t even notice.

You can only see at a high-resolution in a fairly small area, and even that has a big fat blind spot right exactly in the middle, but you still walk around thinking you have a ultra-high resolution panoramic view of everything. Why? Because your eyes move really fast, and, under ordinary circumstances, they are happy to jump instantly to wherever you need them to jump to. And your mind provides this really complete abstraction, providing you with the illusion of complete vision when all you really have is a very small area of high res vision, a large area of extremely low-res vision, and the ability to page-fault-in anything you want to see-so quickly that you walk around all day thinking you have the whole picture projected internally in a little theater in your brain.

This is really, really useful, and lots of other things work this way, too. Your ears are good at tuning in important parts of conversations. Your fingers reach around and touch anything they need to, whether it’s a fine merino wool sweater or the inside of your nose, giving you a full picture of what everything feels like. When you dream, your mind asks all kinds of questions that it’s used to asking the senses (what’s that? Look over there!) but your senses are temporarily turned off (you are, after all, asleep), so they get back sort-of random answers, which you combine into a funny story in your brain called a dream. And then when you try to recount the dream to your boyfriend in the morning, even though it seemed totally, completely realistic, you suddenly realize that you don’t know what happened, actually, so you have to make shit up. If you had stayed asleep for another minute or two your brain would have asked your senses what kind of mammal was swimming with you in the rose bush, and gotten back some retarded, random answer (a platypus!), but you woke up, so until you tried to tell the story, you didn’t even realize that you needed to know what was in the rose bushes with you to make the story coherent to your partner. Which it never is. So please don’t tell me about your dreams.

One of the unfortunate side effects is that your mind gets into a bad habit of overestimating how clearly it understands things. It always thinks it has The Big Picture even when it doesn’t.

This is a particularly dangerous trap when it comes to software development. You get some big picture idea in your head for what you want to do, and it all seems so crystal clear that it doesn’t even seem like you need to design anything. You can just dive in and start implementing your vision.

- Joel on software