I have a crazy amount of different jobs, so the way I manage that is to not do more than one at a time. It's like old computers that had small memory chips, they would do something called swapping, where they would fill the memory with one task, do it and get it out.
Looking back... it's hard to understand what all the fuss was about as things changed in just a few years. When you look at all the things that have happened in the world, it seems very small.