Hmm...I'm not really crazy about that term. I was born in '75, slightly before what most consider a Xennial (77-83, coincidently the same years the original Star Wars films were released). I can remember computers and technology being at the forefront of my childhood, from the Speak and Spell I had as an elementary school student, to calculators, early computers, and then the beginnings of the internet in the early to mid 90's. My college experience perfectly mirrors the statement that "digital adulthood" group that basically grew up without the internet but that it came on so fast in our teens and college years that we adapted to it in real time". That part is definitely real.
I know many in my generation who didn't adapt to computers or the internet at all, beyond looking at the web or using their phone. They are computer illiterates, most of them chose that.
Speaking of which, when I took a job on a large project 10 years ago I was stunned at the number of millennials who do did know how to use a real PC. They could use their phones and Chromebook, but when it came to navigating their way around a PC many of them were clueless.
Yeah, you're the same age as my older sister (also '75), while I was '78. I do think there was a big difference, even between the two of us.
I don't think she interacted with the home computer much in high school except for word processing. So for her it was a fancy typewriter. In the one year she attended college (lol), I don't think it was very common for students to have their own PC yet. But by my freshman year, it was very common. And then email was JUST starting to come on in regular usage while I was in college. I couldn't email my parents--they sure as hell didn't have email. I'm pretty sure I couldn't even email my sister at that point. Although she and her BF (now husband) were operating his marina on Lake of the Ozarks at the time, I'm not sure they had email accounts associated even with the business.
Now, part of the difference between my sister and I, like utee's experience, is that I was a techie nerd even back in high school. My sister is very smart, but she is absolutely NOT a techie nerd. She's the opposite. So it's possible I was simultaneously ahead of this curve, while my sister was behind it. I think you may have made use of that early-mid 90s connectivity and internet in a way that I did and she didn't, despite you being the same age ahead of me as she was.
But I still consider it wild the degree and the speed at which it changed the world. And then advance another decade and you add the smartphone... Someone who lived in 1920 might recognize the world of 1980. Probably the biggest changes in those 6 decades was TV, widespread electrification, and air travel. Someone who lived in 1970 would probably not recognize the world of 2023. We carry around, in our pockets, a portable communication device that can give us access to nearly all of the world's information... In seconds..