Sorry, that was my meme version, the full version is
Don't be stupid
In Christian speak it is: 'be thee therefore wise as serpents and harmless as doves' (Matthew 10:16)
In Buddhism it might be one of the Spokes of the Wheel of Dharma:
Right Understanding - of reality as it is not just as it appears to be
When I adhere to that command I feel commanded not to hold false opinions.
So if an opinion I've held for years becomes suspect I check the evidence and if it is insufficient then out goes the opinion, as that is what I feel commanded to do.