This is interesting-- I've been riding for 14 years now (as an adult). I've been dealing with my left hand going numb for several years now-- tried no gloves, no padded gloves, moving hands around, etc. I finally rotated the handlebars so the hoods were further down. From some fitting method you hold a straightedge against the bottom side of your drops so it points in the same direction as the bars. You try to get it so the straightedge is pointing towards the rear brake. I didn't get it exact, but before I changed it I was way off. No more numbness- even with padded gloves.