If my mind is just playing placebo effect tricks on, fine by me. Though my opinion is you are playing a mind trick on yourself in believing that nicotine has that great of an effect on your personality. You are who you are. When you quit nicotine completely, sure you will be irritable as any other junkie without their fix. But as time goes on and your body and mind get used to no nicotine, you will return to who you are. You do not need nicotine to suck it up and be nice to someone, you will be able to do that all by yourself without nicotine (though none of us really want to).
Nope. Something is going on that affects patience. My husband quit smoking three years ago. Prior to that, he was a pretty mellow guy who took things in stride. That's the kind of guy he was all his life. Now, he is very prone to flying off the handle when we are out driving in traffic, and little things seem to get to him more than they ever did.
This is NOT a case of him playing mind tricks on himself because he did not notice this had occurred until I pointed it out to him a couple of months ago. If it is a case of waiting for the nicotine withdrawal symptoms to wear off, I would think that three years is time enough!