Keen powers of observation

I wore a pair of pants yesterday that I bought....at least five years ago.

I've worn them dozens and dozens of times.

Yesterday, I felt a tag poking me. When I checked it out, I saw a 2 x 2 tag that says REMOVE BEFORE WASHING OR WEARING.

Question 1:  How the heck did I not see or feel that tag ONCE in the last five years?

Question 2:  What the heck was supposed to happen to me (or the pants) if I didn't REMOVE BEFORE WASHING OR WEARING? Apparently I've been living on borrowed time...