"My dream has always been to leave something behind me when I am gone, so far I have failed in that, I failed to invent the hoover, don't understand the mechanics of a kettle...will always fail at getting even a coffee making job at NASA."
You can pass on your wealth and knowledge to the next person in your family. Train your son or daughter to do the right thing. When you pass away, then transfer your wealth over to them so they can run with the ball. Make sure that they also have the proper knowledge, discipline and (above all) drive.
There are many other people behind the Warren Buffets, the Donald Trumps and the Bill Gates. However, you never hear about these other people that helped them get to where they are. In my eyes, those people are just as important (if not more).
You say that you didnt leave your mark? I say that your wrong. Make as much wealth as you can and pass it on to someone else. Sure, maybe you wont invent something or move the markets, but you can pass it on to someone else who can.