The Benefits of Profiling in the Book

I remember an experience where we were storing some data in a list and we had to look up some feature about it. And the code was supposed to be something kind of like real time. And it was just too slow. So I actually threw into a profiler and found, oh my gosh, it's spending 80% of its time in this list finding the item. That really stuck with me because wow, yeah, it was pretty interesting.