whilst I have been joking earlier in the thread I did remember another reason why I stopped using my go pro.
I was training in a PA38 at a busy flight school. The aircraft were in use for the majority of the day so when my turn came I would have to walk out on to the apron with my instructor to carry out the walk around/ refuel etc. after the external checks were complete the two of us would climb into the plane and you would be expected to start on the internal checklist/getting the ATIS etc.
There wasn't really a good opportunity to turn around and stick the suction mount onto the rear window and then switch it on without disrupting the lesson.
This is why the first good footage was of my solo flight because I had the time to do this without anyone else in the cockpit.