To cure his insomnia, Seth Roberts tried exercise, calcium supplements, and adjusting the lamps near his bed. In the end what worked was delaying his breakfast until 11am.

Roberts did the same with dieting, trying an endless combination of things and weighing himself constantly. He found that drinking unflavored fructose water between meals did the trick, and he lost 35 pounds.

The crux is this, how do you generate useful/correct hypothesis? The thing is there is no guarantee that you will ever arrive at a correct hypothesis, so you might end up in an endless cycle of trial and error without getting anywhere... pretty frustrating.