I have had that feeling a bunch of times in my life. The classic example is my iPhone. I bought it in July of 2009. At the time, you could still take out the AT&T SIM card from one phone and place it in another. I wasn't a huge smart phone guy; my phone before the iPhone was a disposable, pay-as-you-go phone I bought on New Year's Day 2009. As one could imagine, I bought the cheap phone in an emergency. I put in my SIM card from my old, destroyed phone, and I was off and running just fine.
When I bought the iPhone, I did so to take a look at these things called apps. It was for work, as I could see the iPhone as being an important new way for my clients to reach strategic audiences (I work in marketing). I figured I would flip the SIM card back between the iPhone and my pay-as-you-go phone as needed.
Well, it turns out I never used the pay-as-you-go model again. And I truly can't remember not having the iPhone.
I also can't remember what life was like before HD television. I do remember, before HD, that I would sometimes prefer to go to a bar to watch a really big game, just to experience a better view on better televisions. I have no such motivation now.
I am still waiting for the same feeling with my iPad. Time will tell.