mild and wild are almost the same word.
mild, clearly has an “m” and wild a “w.”
if you look at an M as if it were collecting water in the rain, it’d only collect a little, and deflect twice as much. It’d very mildly collect water.
whereas, W would collect more than it’s tiny base even could expect, and thus breaks the standards by overmatching it’s potential wildly.
Thus they have the same root “ild,” which I am inferring has to do with a way to do something (a root that means adverb), and the first letter is a shortened way of even demonstrating the difference between that behavior.
Good morning, brain.