This is the reason...

I was woken at 5.15 ...
Was yawning by 11...
Short-tempered by 2...
Grumpy at 6...
In bed by 10.30

The moral of this blip? If you've bought a second hand watch from Oxfam with no instructions, and you can't work out how to stop the alarm going off in the wee small hours, for gawd's sake remember to leave it downstairs!