If you can’t open a 2 liter bottle (every so often I swear there’s a glitch and they’re not perforated the way they should be) wrap a rubber band or two around it and try again. Magic! (Probably not a new trick as in hindsight I recall us having some kind of rubbery disc for that purpose when I was growing up, but since I don’t see those in stores anymore the rubber bands are a great rediscovered hack.)