I discovered ridge gourd only after moving to south India. The first time that I bought it, my motivator was curiosity – I had no idea how this vegetable, which looked a cross between sponge gourd and bitter gourd, would be cooked, or what it would taste like. Pushcart vendors outside my apartment stocked ridge gourd in heaps, and it seemed to be the freshest, most abundantly available vegetable on sale. One day I walked up to a vendor, pointed and tried to ask him in gestures (I did not know Kannada) to name the vegetable. In response, he swiftly wrapped two ridge gourds, held out the package to me, and named the price.
And so I returned home, ridge gourd package in hand, and typed into Google image search: "long green Indian vegetable with spikes". Google did not disappoint – I found not just the name but also many ways to cook ridge gourd.