Guys don't lie.
They just don't know what they've done.
Most guys have what science has labelled — in lay terms — "Male brains." Most females have "female brains." Neither is stuck in one gender or another. Some guys can keep up with women. Some women lag behind at a man's pace.
Women can't really lie to themselves. Our brains have a tendency to have up to eight hyper-linking layers, all working at once. It's what gives us that thing the guys call intuition; we can see all sides and fractions of a problem and put them together and find the answer. It's what sometimes causes us to suffer from such tremendous inertia in getting started. We can see our own weaknesses, the problems we may encounter, the trouble that may come.
The male brain, on the other hand is often made up of two sides with an impassible wall between them. They can entertain two mutually-contradictory ideas at the same time. God is Love so you should Fear Him is a typical male thought. So is Sex is Filthy so reserve it for the person you marry. Male thought makes us attack people and claim that once we're finished with them, they'll love us.
How many times have you seen a guy say or do something — in front of witnesses — then five minutes later he stands and swears up and down he never did or said it? I mean, you can have an email record of what he wrote, you can have it on film, but he will absolutely swear he never sent it or did it or said it. He will absolutely think he said something out loud — a roomful of people can witness that he never spoke — and he will believe he said it.
I think this is going on: as we know, one side of the male brain has to do with action, the other with communication. A guy DOES something, but five minutes later, if he is spoken to about it, the information from the action side can't make it past the wall between the two sides of the brain.
They're not lying. They simply cannot, for the life of them, figure out what you're talking about. There's a wall in their head that won't let them access the information.
Remember that some women have male brains. Those of you guys with female brains know what I'm talking about.