Is it normal to not really think about people unless it's convenient to me?

For starters, I'm not diagnosed, but a few months ago I found out that my mom suspected me of being level 1 autistic when I was young, but was too afraid to have me tested. I've been going back and thinking about all the things that made me feel different, and I think this is the biggest one.

I'm not quite sure how to accurately explain it, but I just don't think about people that often unless I interact with them. Like, when I go home after being at college for months, my mom says she misses me and I just say it back out of courtesy. I love my mom, but I'm not sure I can say I've ever missed her before. This goes for her, my sister, my best friend, even my partner. Because of this, I have to make an active effort to text them every day or I'll just forget to talk to them. This has caused concern in my loved ones several times before.

Also, this might bleed out into why I'm so introverted. I always say that when I'm at school I'm there to learn. I say this because I never make an effort to socialize at school. I never found a good time to talk to anyone I didn't already know. I was always busy doing class work, eating lunch, or killing time on my phone, but it never occurred to me to try talking to other people. Honestly, I still don't talk to strangers unless they talk to me first, and then it takes multiple interactions for me to seek them out for socialization myself. That goes for people I see every day on campus or at my job.

TW: Another branch of this is my response to death. There's been times when beloved pets in my household had died in a way that directly involved me and I was absolutely destroyed for multiple days, yet when I found out my grandma's cat (who I loved very much) had passed I hardly reacted. I knew I should be heartbroken, but really I was more upset over how not upset I was.

I know I'm not a soulless individual. I love my friends and family, but I don't understand why it's so hard for me to think about them if I go more than a week without seeing them. Thank you for reading. I don't go here very often, so if there's a problem with anything in this post, please let me know and I'll fix it right away.