Have a Jesus and Mo.
Stupid, no, but unreasonably credulous, yes.
It’s human to be unreasonably credulous, of course, but it’s also human to be able to learn to correct for that. It’s human to learn to correct for that but still fail to correct for it on all occasions – in other words it’s human to correct for unreasonable credulity on things one is not too invested in but fail to correct for it when one has a motive not to.