We lie to either get sex or power tools. With girlfriends or potential girlfriends, its all angled at the ‘prize,’ so to speak. It would be nice if women fell into bed with only the truth, but if we have to lie to get someone to give it up, so be it. Women fall for the lies at a high-enough frequency to make it a pretty good risk/reward payout. If your little lies get found out and the relationship is damaged and she walks, well, you still got most of what you wanted.
With wives, we lie to avoid endless pestering. So let’s see: I could either beg my wife to ‘allow’ me to buy that $250 router I’ve had my eye on at Lowes, or I can just go buy the damn thing and figure she won’t see it among all the other thousands of tools I already have in my woodshop. Either way is a hassle, but at least with the second I have the router.