how many does it take to change a light bulb

So I have been changing out light bulbs - 1,2,3,4,5,6.....7? Maybe more. I find it interesting and amazing that sometimes we think we live in enough light - that it's bright enough, even if we know that a light bulb is out. And then when we finally decide to replace the bulb for whatever reason...we are sometimes surprised how much light we really were lacking, or how much light that additional bulb adds - at least I am. Every time I replace a dead bulb for a new one - once that last twist goes in and the light goes on - my face illuminates - smile.