Back in the early 80's, an old man came into my shop. He owned several BSA's, a model A Ford, several Harley Sprint's and a 1970 FLH (which I bought). He made the comment to me and it has stuck with me to this day.
He said the two greatest things God ever allowed to be invented was the John Deere B series and the Harley Davidson 74. Ain't it the truth.

 

As a long time owner of a '51, 74, I agree!

 

While it's great to be nostalgic, there's nothing on that list that I'd ride off into the distance with any reasonable expectation of making it back.

 

Well ... With a pair of vice grips, some duct tape, a spool of wire and minor mechanical skills you'd stand a good chance ... now, on a late model scooter, good luck if something "gives up" :>)

 

P-38 could not live with out one.

 

For the average person, I think the two most beneficial inventions of the 20th Century was the internal combustion engine and the computer.

Just think about the amount of physical work and manpower hours that were reduced by these devices.

 

Welding machines !!

 

The invention that preceded the miniaturisation of computers and all electronics is the transistor.

 

The computer morphed into the smartphone...which will probably cause the end of mankind as we know it...

You always see in Sci-fi movies/shows...where in the future the people have gone back to the stone age...

Because they forgot how to repair the machines built by their ancestors...that will come to pass

 

Toilet paper.