Once I thought about something insanely difficult in a dream. It was a strategy to keep my stuff safe. When I woke up and tried to rebuild that plan I got headache from it. Also, I can compose mussic in dreams without even thinking at it. But other things are a lot harder for me to think about dreams. For example I fail at pretty simple math tasks in dreams. Like the one time, where I had to calculate how much money we need when we want to buy 112 Big Macs
if one costs 2.50€. I came on an number like 50 or so...