Some decent advice here already, so I'll provide something from another angle by just picking something for you. That is, if you continue to be bothered by this

Some decent advice here already, so I'll provide something from another angle by just picking something for you. That is, if you continue to be bothered by this, and think you have the actual capability to become an expert in multiple things (rather than a fanciful desire), first become an expert in longevity therapy research and help bootstrap yourself and the rest of the species into having enough time to pursue whatever you/others want.