YES, I AM NOW AWARE THAT IS VERY STUPID AND WRONG. But I just had a first impression when I saw it, made a (seemingly) logical conclusion, and just went on with my life, being dumb as hell about toilets and not knowing it. Eventually someone informed me of the TRUE reason for it - it's almost the complete opposite of what I thought it was: it allowed women easier access to wiping themselves without having to risk touching the gross toilet bowl. WHICH MAKES A LOT MORE SENSE THAN RESTING MY JUNK ON A GROSS TOILET.

My mom didn't know what the oil change light on the dashboard was. She went to her friend (who did a popular morning talk show in Montreal) and asked "why is there a gravy boat light on my dash?" The next morning the entire city knew she'd said that.

Not sure if this is a feature on all smoke detectors, but finally after five years of owning my house and getting used to grabbing a chair and knocking the batteries out of it, I just hit the test button on the front when it went off while cooking. "Hush mode activated". It turns it off for fifteen minutes and automatically turns itself back on. It felt like unlocking a secret character in mortal kombat.

Not me but my dad. He always likes to look nice and put together. One day before church (I was maybe 14), I asked him if he had a lint roller. He got it for me, and it was absolutely covered in lint. So I ripped off the top sheet. Dad's eyes widened in shock. "I always thought lint rollers were so expensive for how few times you could use them!" He never knew there were more sheets underneath. Dad was in his mid fifties then. He hates when I tell that story.

When I was in first grade, our teacher had these really cool cookie jars. One was a dog that made barking sounds when you opened it, one was a cat that meowed, etc. We all loved those cookie jars. I realized literally yesterday that they make sound so the adults know when someone's getting into the cookie jar... It's fucking genius.

That the approximately correct amount of loose leaf tea for one cup is..... a teaspoonful.

You know the plastic hooks on vacuum cleaners that are used to wind the cord around. Well the top hook will spin 180degrees to release the cord, so you don't have to spend time unwinding. Didn't realize this till my wife showed me well into my 30's.

Clapperboards in movies. They're used as a visual reference to sync the audio and the video together in editing.

I had no idea that salad spinners were to dry your salad. I thought they were to mix your salad dressing or some shit. We got one as a wedding gift, so I loaded one up, dumped some dressing in, and spun a ton of the dressing off of the salad. This made me think the product was to apply dressing flavor to all of your salad bits, without dealing with all the calories that can come from overloading on dressing. So naturally I thought it was a total waste of time and money, and tossed it into a cabinet never to be used again. A year goes by, and I see a comment on Reddit about salad spinners and how they are such a game changer and so worth it, and I thought people were just batshit insane. Nope. I'm the idiot here. They're to dry your washed salad bits so you have nice, crisp, not-soggy salad. I had no idea, and the box sure as hell didn't tell me that.

When I realized that the division sign '÷' is an empty fraction

I bought a used pickup truck in the late 90's that had an electronic key fob like any car these days. It had a couple other buttons as well that when pressed did nothing. I asked about it at the dealership and they told me it was probably for a remote start that wasn't hooked up. After two years of driving that truck around in cold Chicago winters, I sold the truck to my brother when I bought my first new car. One day while talking to him he started the car up with the remote starter. I stared in complete shock as he explained that you have to hold the button down.

It took me four years of owning a car to realise I could spray washer fluid onto the rear windshield. I just assumed it only sprayed the front and I would just occasionally throw a bucket of water on the back if I needed to. Then one day I just noticed an odd symbol on a lever I hadn't seen before. Held that mother down for about 10 seconds before a massive gush of liquid burst out the back and changed my life for the better.

Went into a store and purchased a nice suit for work but forgot to bring the coupon I was going to use. I asked about it while checking out and the girl told me she's sorry but can't help me. She then placed the same coupon on the counter and asked if I had dropped it. I must have been distracted because I denied that it was mine 3 times before I finally understood she was trying to be nice and give me a coupon. Felt really dumb.

After high school, I was working a temp job in a business remodel. The wood floors had been put in and the contractor had a big roll of paper that he taped down to cover the floor to prevent scuffs and a scrapes while the work continued. One time I touched the roll of paper and noted that it was somewhat sturdier than normal paper and reminded me of craft paper that we used in elementary school. I remembered that as a child,, the teacher always called it (doink -- moment of realization) construction paper.