I am the same way, have a bunch of things I would love to do, but don't have the time. Once thing I noticed is that at least in the past 2-3 decades there are more and more fields opening up to DIY projects that used to have a really high bar for entry in the past. DIY biology, robotics and other electronics and many others. So I think by the time we could fill one lifetime with projects, things would pile up enough to take another few lifetimes :)