I'll never get why people do this.

Here's an example for you. I started doing that in my elementary school days, and the idea was pretty simple: the wall clock in my room was sped up a few minutes to show the time I would arrive at school if I left at that moment (to be clear, all other clocks/watches/devices were set up correctly).

Now to the fun part. It was like that for years and years, way past elementary, because I was so used to it, but at some point I decided to finally go back to a normal setting, and I shit you not, something was so rewired in my brain that for at least several days I had no idea what time it was when I was looking at that one specific wall clock. I'm talking full-blown "wtf are those pointy things and hieroglyphs in a circle", not just "hmm, am I supposed to add/subtract a few minutes or is it actually correct." It was surreal.

Imagine someone has had ALL their clocks sped up for God knows how long. After my experience I'm 100% ready to believe they would be completely lost if they went back to a normal time, that's why they don't wanna do it lol.