What we tell ourselves is "validation" is usually no more than a misguided belief backed by encouraging , but insignificant, data .
If you're being truly scientific, you're seeking invalidation. What, if it were true, would cause you to majorly adapt your current course?
Critics and naysayers are useful here. They'll flag up issues - and sometimes we'll ask ourselves - how can I quickly find out if they're right? And if they are right, what do I need to change?
(Thanks to Bert Heymans for the positive way to use critics.)