I tend to get a little obsessive / lost in the weeds on everything I touch 
My sandrail:
I tore down to the bare frame, rebuilt the motor, rebuilt the transmission, upgraded the suspension, assembled my own EFI controller for the new motor…I even did most of the work making the suspension seats (I bent the steel frames, cut and glued the foam, installed the slings and covers) but that last part was mostly because I was working for the company that made because my own business was a bit slow at the time 
I’m also into amateur radio and have always enjoyed building my own radios more than buying them.
I was into photography for a long time (even majored in it in college) and along with making my own pinhole cameras did some experiments with making my own emulsions and coating plates.
I even get that way with cooking. A few weeks ago I made beef stroganoff and while it simmered made my own noodles from scratch to go with it.
For a few years the only beer I drank was what I brewed myself. Which led to me growing my own hops (I considered growing my own grain but didn’t have the room!) I also make mead from time to time and have seriously considered getting my own beehives…but I REALLY don’t like getting stung 
I really relate to the “How to Make Everything” youtube channel where he tries to make all kinds of things from the ground up. I just like getting into things I’m interested in and diving as deep as I can to really make them my own.
It’s going to have to happen sooner than I expected! Think I still have enough ply for one more…but this stand probably won’t support two racks so I may have to build something better…