When Gutenberg died the paper book had well over 500 years of life left. When James Watt died, the steam engine had over 150 years of useful life left. A couple of weeks ago Howard Scott, one of the creators of the LP, the long playing record, died - having seen his invention cease into a niche product well before his death. When Bill Gates dies, Windows will be long gone. The lifetime of technologies is dropping dramatically. Where once, inventing something meant a life in eternity, it now just means 'a few years of relevance'. It's becoming harder and harder to leave a mark on society that will outlast you, if that's the kind of thing that motivates you.