Here is something that makes my brain hurt, though it's probably my own fault: when people reference the "second hand" of a clock. Do they mean:
1) The hand that counts off 60 seconds in a minute, which is usually the thinnest hand and often red?
2) The hand that counts off 60 minutes in an hour, because it's the #2 hand, the hour hand being #1 and the red hand being #3? (According to the order in which you would give the time--hours, minutes, seconds--and also a sort of importance measure.)
With all of my qualifiers on #2, I'm guessing people are usually referring to #1. But apparently at some point in time I was taught with, "What number does the first hand say? What number does the second hand say?" and now I'm screwed up for life. Thank goodness for digital.