When putting forth a scientific hypothesis, you should be your own greatest critic. You don’t want colleagues finding holes in your reasoning before you do. It looks bad and it reveals you didn’t do your homework. A good way to attack one’s own work is to step back and explore whether a completely opposite explanation can be constructed from the same data or from data you may have overlooked. If you succeed at dismantling your own hypothesis, it’s time to move on to another research project.