It's a bit like what happens when an intelligent coward is met with contrary evidence. He will turn away from the truth and go to great lengths to rationalize it away, and in doing so, he will blind himself to the truth. Making that a habit through repetition only deepens the vice and unravels the mind, making it increasingly difficult to dig yourself out.
Not that you need to bullshit them, but often a woman tests a mans abilities before she decides on a relationship. The tests are many. Some are of loyalty, some of intellect.
But many are of how quickly you can react to unknown, hard to grasp things. It’s called “banter” usually, and it’s absolutely vital in many cultures and areas to attract someone.
Banter is essentially “bullshit”, except it’s highly entertaining. It can contain tons of truth (it can be almost all truth and even more so than a dry analytical conversation ever could, in a Straussian way). But the ability to play along, take up characters, bluff, and know exactly when to push things and when to let them up, to understand the “game” of having fun through conversation. That’s basically as important a thing you can learn, absolutely vital to reproductive success, and honestly one of the most fun activities that exists.
Sure, you can draw a line and say stupid banter is stupid or pure BS is BS. But you’re totally missing the point and the fun behind it, and the real usefulness. Talking dryly about science wont convince people - but giving a good fictional story with some (wink wink) bluster and can convey much richer meaning and keep people engaged.
Another problem is that the truth often doesn't matter, and the intelligent cowards knows it. He won't deny the truth, but he will explain why the truth doesn't matter.
> he will blind himself to the truth
Not necessarily. He would try to not turn to cynicism. But cynicism can be very tempting.