When did you give up trying to convince your boss of anything?

I gave up after about 6 months. I realized that I was never going to change his mind, so I didn't bother trying.

Before that period I tried to persuade and argue. I was all motivated and energetic. Slowly, as I saw idea after idea never become implemented, I made fewer and fewer suggestions.

Eventually I stopped making suggestions altogether. I reasoned that since none of my suggestions were implemented, it would be useless to continue to make suggestions.

I also noticed that my boss forgot things within a few days. At first I energetically reminded him about his decisions, figuring that everyone forgets every now and then, and that it's helpful if someone reminds you.

Then I began to realize that he forgot A LOT of stuff. And would often change his mind. I began to realize that what I did ultimately didn't matter. If I reminded my boss of something, he would just forget a few days later.

Or he would remember but only partially remember and it would be a bastardized version of the original idea. Or he would forget the ultimate purpose of the idea or give credit or criticism to the wrong person.

It became clear that it was much easier to simply not do anything. I think this is called "learned helplessness". The idea here is that you can do two things when you have this kind of boss:

1) Spend a lot of energy trying to get your way, and probably failing.

2) Spend no energy trying to get your way and not failing - but then not really getting what you want.

When I spoke to people about this situation the (fatalistic) advice I got was, "You're not going to change these people's minds so don't bother. Just do what they want and concentrate your energy elsewhere."

Following this advice is certainly easy, but unsatisfying.