I can guess the answer to this:
Person goes to loo, needing a poo. Operates lightwitch. Bulb goes "tink!" and flashes out its last photons as yet another Ballotini fuse* destroys itself (in their oft-repeated yet unsung sacrifice to protect you), then goes dark and silent forever. A bulb has died, yet who would mourn its passing, when a different kind of passing occupies the owners mind?

The Crappee is then faced with dilemma: Waddle off (with urgent need of a dump) in search of fresh bulbs; OR, Crimp one off there and then in the Stygian gloom.

They could have kept spares in the toilet**, but that still leaves (at a minimum***) the steps of removing lampshade (and if it's a full bathroom, chances are it could be a full waterproof fitting) and slotting a fresh lamp in; while you're aching to crap.

* Other fuses are available.
** The room, not the fixture. That would be disgusting and unsafe.
*** The bulb may need to cool off, or power isolated, before it can be safely handled.

(Can you tell I've had a little fun with this post? Not to mention the multiple edits.)
(The Incredible Sulk Finally remembered his password on, Mon 22 Mar 2010, 0:47, 1 reply)

Or just wait until the daytime.

( jim_bob can herd cats., Mon 22 Mar 2010, 12:16, closed)

or become a timelord.
They don't have such troubles; or do they?

www.youtube.com/watch?v=ZahysN2sIIw
(The Incredible Sulk Finally remembered his password on, Tue 23 Mar 2010, 0:16, closed)