We all have our little idiosyncrasies. One of mine is that I worry that one day most people in the world will die and only a few of us will be left - think an scenario like in Stephen King's
The Stand.
I worry that if this happens no one will know how to do anything, like grow food, build houses etc because most of the world's population aren't engaged in those sorts of earthy jobs. There seem to be a lot of us who work in offices and make no obvious contribution to the day to day survival of the species.
Today I decided that should everyone else die I would really like to be able to make glass. I like glass and I think I would miss windows if I didn't have any. So I googled "glass making" and now understand the theory behind how to make glass.
My glass making knowledge will also be helpful if I ever get transported back to 16th centenary England and have to win over the royal family by helping them refurbish their castle.
You might call it odd. I prefer the term idiosyncratic.