A lot of the time you can't define exactly why you can't do something though. If someone asked me to just write a natural language recognition app, I'd be quit

A lot of the time you can't define exactly why you can't do something though. If someone asked me to just write a natural language recognition app, I'd be quite excited to give it a go, but instinctively I know it's a heck of a task. It's infeasible rather than impossible. A bit like asking a golfer why he doesn't just hit the ball straight on the green every drive. It's instinct to attempt, but difficult to explain why it's not going to work. Not to mention if I had to explain every time why I can't just hit the green, I'd get pretty pissed off with people asking!