It was rather by accident that he drank something.
An event came up and I accidentally clicked the first option not minding it was Kiko, the GC. I think it was the one that makes the villager lose skill.

And as you may have noted, I am a newbie and I dont know yet how to post pictures. I clicked on the tips provided by our friendly virtual friends but havent gotten around to doing it.

Yeah I still have cute brown-haired Kiko running and creating berries though I have now finished vv2 after 26 triplets and 3 runners alive. you should see how fast I make stews:)