Dreaming

After class the other day and I felt like I'd been in one of my recurring dreams. There are several different ones but they all involve trying to do something and not being be to do it. The punch that always goes in slow motion or running and your feet not able to push against the ground. In class I was trying to get across a concept and no matter how I phrased it it just wouldn't pass from my brain to the students, like a balloon flying off uncontrolably finally landing on the floor.
I used to have another dream where I was sitting a maths exam and I realise I haven't been to class all term, I try to think of times I was in class and can't think of any. A few months ago I had a dream where I succeded in doing something, can't remember what it was though.
People sometimes say "I hope your dreams come true" I hope mine don't.
I wonder if anyone has dreams where they are hugely succesful and doing fantastic things that they can't do in real life? Imagine waking up from one of those dreams and thinking; oh no, it wasn't true why did I have to wake up. It'd sort of ruin your day. I always wake up thinking thank goodness for that, I don't have to sit an exam I just have to invigilate one. That's why I'm always so cheerful.