If there’s one invention that yet ceases to exist that I’d die for it would have to be a time machine. I often think that if it was invented the public wouldn’t be allowed to use it. Or maybe it’d be really expensive to use it. Or perhaps years and years after it is made it will be common for the public to use it and there would be time machines everywhere in cities(I think of the show futurama) and it would be easy access for people to revisit their past or go on vacation in the past. But if I were able to use a time machine then I would go back in time probably to 2011 and redo everything very carefully and make all the right decisions. I think then I wouldn’t have as many problems and have a happier life. Oh well though, you live and you learn from your mistakes.