I expect most people my age have had great ideas they never patented. I’ll list a few here just to make myself feel better and to encourage you to post yours (these are ideas that are already patented or can’t be)
30 years ago when we got our puppy I put up some bells on the door and taught him that ringing the bells means we’ll take him out. He never abused the privilege. Now, doggy bells are every where.
My best invention was 25 years ago. I suggested to the people I was working with that we create a drop down button. The idea was a button with an arrow next to it. You click the arrow and a small menu appears. Whatever you pick from the menu appears as the text of the button, and clicking the button takes that action. Woe is me, it is everywhere today.
Also about 25 years ago I conceived of Quake Awake — I had read that people who awaken at the beginning of an earth quake are likelier to survive than those who sleep through: hence: Quake Awake. It would look like a smoke detector, and you could set the sensitivity, the necessary duration of quaking, the times of day (if you only want it to go off if you are sleeping) and etc. I even had a patent lawyer tell me it was a great idea. Woe is me, you could now write that as an app in about 4 hours.
Post your almost-inventions.