Seven. One to install the new bulb and six to figure out what to do with the old one for the next 10,000 years.
or
Finding a cabinet position for the thing on his head!
or
Weeeeeeeeeeeeeeeeeeeeeeeeeee
or
Woke up in the fireplace.
or
His breath.
or
Just one, but he/she will spend hours checking for technical problems.
or