Ive had many good times spent working on something, usually something new that I was trying to figure out and understand, and looked out the window and WTH?! the sun is coming up!
Staying up all night and not realizing it is pretty cool.
Sometimes I get so involved in something I cant remember what day it is, where I parked my car...
I have to stop and think for a minute then it comes back.
its not forgetfulness, its pushing the unimportant things aside while your brain is 100% on one problem.