Worshippers at the altar of gaming as we are, we always suspend our disbelief heavily for the fun of video games. But there are a few things that I always think about, despite the fact that I'll believe in lots of absurd ideas in games. I'm not challenging these ideas, just commenting on them.
The first one is jumping. It's funny to me that there is such an abundance of jumping in video games. So much so, that you might be surprised when there is no jump action in a particular game. But in life, very little jumping really happens. I don't jump too often. Sure, I don't kill aliens or hunt terrorists often either, but this jumping thing makes me laugh.
The other idea is more prevalent to older games. Why is it that when you touch an enemy, you are hurt or even killed, and the enemy leaves without a scratch. I know in some games they die as well, but it's kind of ridiculous to think that whatever tough character you're playing is so weak that a person could walk into him and he would die. Imagine if you bumped into someone on the street and were mortally wounded. Is the real challenge of the game to help a total wimp defeat some godlike being? Are the heroes just bumbling idiots? Or are they all suffering from haemophilia?
Again, this is just speculation. I think these things are amusing, but they definitely don't ruin the fun.