Has this been going on for a while, or was it a sudden thing? I don't know about the Friday pattern, but my husband and I have definitely noticed that temper tantrums and mental growth spurts go hand in hand at our house. DS5 has gone through many unmistakable developmental leaps where all of a sudden he seems to go into overdrive and there just aren't enough hours in the day for all the writing, drawing, reading, math, and scientific exploration he wants to do. It's just like what you described--he'll have some problem or project on his mind the minute he wakes up and will have completed ten different activities by noon. At the same time, however, he seems to be even more sensitive than usual and will have zero tolerance for frustration. This usually only lasts a couple of weeks though, and then he drops down a notch again. It's happened so many times that we've learned to just ride it out. If this has been going on for a long time though, I'd be more concerned.
