I think there are a lot of factors to it, beyond individual personalities, like the age you get them at and what kind of experiences they've had prior to you entering their life. My Astrid was estimated to be around 3 when she came home with me. It's been...a year and a half? And I still can't touch her. We have a treats routine where I can slowly reach towards her and she'll sniff my hand then take a step back, and that's pretty much the closest we get. The way she reacts to me reaching up, especially with something in my hand, like a wand toy, makes me wonder if she had bad experiences with humans at some point. I expect things to speed up after we move within the next month, once she gets settled in, because she'll be a little more forced to be present and part of the household living with just the fiance and I in a small space. I also plan to get her a better socialized companion once she's settled in, as she seems to be a very cat friendly cat. I think those things will open her up a lot. She rolls and rubs and does the whole song and dance excited to see me, I feel like once she learns how nice it is to be pet she might even pass for a regular (but shy) house cat one day.