If you spend more time learning on one side you'll use more of the light from those bulbs and they'll burn out quicker. That's why you should switch bulbs at the same time you flip your mattress, which can be done when you change smoke detector batteries, which should be done when we change the clocks, which SHOULD NEVER BE DONE EVER.
Piano Tuner: You know you really need to get your piano tuned twice a year.
Person: Why don't you send out a postcard like the dentist?
Piano Tuner: Great, next time you get a postcard from the dentist, call me!
