Small shock from mains
You could have felt the shock only in your finger because that small point was where it all entered and therefore had the highest current density, and once it was inside you, the charge spread out while flowing through you thereby reducing the current density. I would think if you were standing on just a tippy toe you would also have felt something there too.
The closest I ever got to be shocked was when I was holding two wires on some ~50V (I think?). I felt a tingling in both my hands where the current entered and exited.