TikTok has become the place for random life hacks and lessons we never knew we needed - from bringing wilted vegetables back to life to repairing broken zips at home in under 60 seconds.
It has now taught us something about our car that we had been pretty clueless about for years.
A man named Justin, who posts under the username @milltj01, has created a video to share a discovery he made about the fuel cap on his car.
He captioned his post: "How did I not know this?"
In the clip, he shows himself removing the fuel cap from his car, as if he was going to fill it up with petrol.
He then points to a 'slot' on the fuel door and hangs the cap on it.
A voiceover says: "38 years on this earth and I just learned this."
His video went viral, being watched more than one million times and garnering over 44,000 likes.
Many people also confessed they hadn't known about this before, with one person replying: "51 years on this earth and I just learned this."
Another said: "I'll be back in a second, I have to check something."
His clip caught the attention of another TikTok user @aketton, who has over 64,000 followers.
He made his own video, in which he goes out to his car to check whether he can also do this.
"No I'm not having that," he says as he approaches the vehicle.
"Oh my days," he proclaims as he realises he also has a slot for his fuel cap.
Ketts then proceeds to try the same thing out on a different car, in this case there isn't a slot, but the door has a small hook on it to hang the fuel cap off of.
He adds: "How did I not know that? I normally just let it dangle and knock about like that."
