My own experience was that 4 was just a really hard age. It is certainly the age that I found most trying (and the age that DH and I decided that there really would not be any more children). DS was highly verbal and sounded much more mature than her really was. He was smart and quick, but not the least bit rational. I kept tryinig to treat him like he was rational, but he was not--he was profoundly passionate and easily overwhelmed by all he was figuring out about the world.
I would suggest lettiing him lead for the amount of time that you can handle it--say 5 or 10 minutes. Set the timer so you both know how long it will last. When it's done it's done. Then do something you can handle, like reading a bedtime story. Or 5 minutes of your game then 5 minutes of his game. The worst part was when there seemed like there was no end in sight. One of my stock phrases was, "I;m sorry, mommy just isn't very good at pretend games. I can only play this for 5 minutes, then I will have used up all my pretend."
But the best news is that this is temporary. Remember to write down some of his crazy ideas and words and games. Because when you want to remember them (like I do now so I could share them with you) they may all be forgotten. When he is 6, I guarantee he will be a totally different creature and you will h ave the games you always dreamed of. DS is 12 and we have family game night regularly and he often beats us using rules we all agree on!
