Years ago (don't remember how many), I converted most of our FREQUENTLY USED lighting to CFL bulbs. I know the package says there's a life expectancy of 5 years, but I couldn't tell you how long it's been since I changed a CFL bulb in this house. In just the past week, I've had 5 bulbs burn out! In fact, there is a lamp on both sides of the sink in our master bathroom and the one on the left burned out Saturday. The one on the right burned out this morning! I'm guessing I changed over to CFL's 5 years ago (heck, it could have been 6,7 or 8 years ago for all I know). The ones that went out in the past week are ALL in lamps we use daily ... bathroom, my office, bedroom ceiling fan and the light over my garage door that stays on all night, every night.
I can't believe they've been going out on an almost daily basis this past week. I'm not complaining mind you ... they've lasted MUCH longer than the old incandescent bulbs would have. It's just astonishing to me that they lasted the same exact length of time. I'd call that consistancy! (or coincidence?)