Alternatively, the classic joke is similar to "Why did the yardstick go to therapy? Because it had too many markings!" But again, maybe not helpful here.
Alternatively, considering mathematical terms: a yardstick is 36 inches. Maybe the joke is about the yardstick being measured in yards or inches. If it's a teenager, perhaps it's 13 inches or something, but that might not make sense. Alternatively, the classic joke could be "You can't handle the straight edge!" (referring to a straight edge ruler as a teenage rebellion theme).
Wait, maybe the answer is something like, "I can't take the measure of your anger anymore!" or "You won't let me grow an inch!" since a yardstick is made of standard lengths. Teenagers are often told to stop growing or something. Maybe the joke is about the yardstick being a teenager, so it's not wanting to be rigid or not growing?