Re: What I do actually miss is..
"....taking the specific ring pulls off of Coke/Pepsi cans and then flicking them."
At some point in the '70s they made soft drink cans with pop tops, two circular "buttons", one large, one small. Normally you pushed in the small one, which relieved the pressure enough so you could push in the large one, then guzzle it down with continuous air flow between the two.
Except I would shake them up, push the small button slightly open against my teeth, letting the extra pressure from the shaken soft drink squirt the liquid out , and completely empty them of liquid, but leaving them still sealed, coz the button sprang back when you did that. I ended up with a large collection of empty but still sealed soft drink cans.