YSK that if your turn signal is blinking unusually fast (like 3 or more times a second), it generally means you have a bulb out.
Why YSK: Your signals alert other drivers as to what you're doing; a signal bulb costs a few bucks and is usually a quick and easy repair to do yourself (consult YouTube); and any place that regulates motor vehicles probably requires you to have working turn signals. So knowing when and how to replace a burned out signal bulb can save you an interaction with law enforcement.
Adding: You can diagnose which bulb is out by turning on your hazard lights and checking all four corners of your car. It'll be the one not flashing.
This is also probably a good time to check your brake lights. Put something heavy on the pedal or have a friend hold it down and check that all three brake lights illuminate. Replacing a burned out brake light is also usually pretty cheap, quick, and easy.
This is like "I'm 16 and just got my car" level of YSK.
Fun Fact: in the dominican republic it's very common for cars to never get any replacement bulbs whatsoever throughout the life of the vehicle. The amount of cars you find on the roads with no working lights is terrifying, just like how their drivers behave in traffic.
For you and me it is, but a lot of people don't really know much about their vehicles, or haven't had the opportunity to learn everything about them.
It's never too late to learn something new.
Next you're going to tell me I haven't had my blinker fluid changed each year.
Relevant username
I just finished draining mine to put winter fluid in. It gets cold up here.
Well, if you have a low brake fluid level chances are that you might need to check your brake pads.
Not everybody knows what you know.
https://xkcd.com/1053/
Is there a part of the US, Canada, Britain or EU that doesn't have a law mandating working blinkers for a vehicle registration on a regular cadence?
My state doesnβt even mandate a yearly vehicle inspection.
You'd be surprised at how many people drive for decades without ever having lifted their own hood.
But more importantly, how drivers behave to pedestrians?