What items from your childhood are no longer in use, available; and would probably baffle and befuddle todays kids?
broken records (or even unbroken ones)
the little plastic insert that went into the big hole of a 45 RPM record so that you could play it on your record player without having to hunt down the adapter
S&H Green Stamps (the S&H stood for Sperry and Hutchinson)
no seat belts in cars and NO digital interface on the dash
land line telephones; and, only one per household, located in a niche in the main hallway with an extremely long (25 foot or longer) coiled chord connecting the receiver to the phone
the cashier counting out your change at the check-out stand, instead of handing it to you in one fell swoop with the receipt
driving your automobile into a service station, running over the rubber hose that sounded the alert bell, waiting in your car while the attendant filled up your gas tank, checked your oil and cleaned your windshield