I am a proud nerd and science/technology enthusiast, and perhaps for that reason it has always caught my attention when people mistake a light-year for a unit of time. As to exactly how long in duration a light-year is to someone who thinks it's a unit of time, I don't know, but I suspect most think it is much longer than a year. I've often heard it used in exaggeration to indicate an extremely long time. ("They had me on hold for 100 light-years!")
Regarding the basketball context, I think a unit of time actually makes much more sense than a unit of distance. In your example of Jerry and Bob, it could be understood that Jerry's skills are developed beyond Bob's to an extent that would be expected if Jerry had been at it for years longer than Bob.
Finally, a minor point of clarification/correction to the sentence in bold: I would not say that a light-year "lasts" for one year, any more than I would say a mile lasts for some period of time. (That being said, if you're wondering how long a mile "lasts" for various Boneyarders, there's a
thread for that.)
