I’m wondering why do people who absolutely disliked my guts in high school or in life generally, add or follow me on social media ?

I've wondered the same thing. Nosey! 😂
Actually messaged one person to ask why. She said that was long ago and we are adults now.
I don't add them though. Treated me like crap back then, don't need or want them in my life in any way now. 🤷