How much of your answer depends on your stage in life, such as academic level?
And totally unrelated: Do you eat cereal for dinner on occassion?
I think that various IQ tests and the likes played an important role in my early life because they got administered a lot. I was pretty much a space-cadet in elementary school, and sometimes my teachers would make reference to them out of frustration. To this day I have no idea how I scored on those stupid things. This has no bearing on my life as it is now, but it comes to mind sometimes when I remember what a strange child I was.
Right now, the MCATs are pretty important to me because I'm using them to apply to Masters programs. Gah! It helps to put these numbers in perspective though.
And also, no, I hate eating cereal in general and I think my mom is strange for eating it at night. in bed.