Hi everyone,
I once heard on TV "the stupidest thing I've ever done"... I am wondering why, despite the two syllables, this comparative is not 'the most stupid"... could someboby help me understand, and inform me in case there are other exceptions ?
Thanks in advance

Yeah, there are a few. Pretty is another. So is silly. Stupid is the only one I can think of that doesn't end 'y' though.

See this lesson on comparatives and superlatives from adjectives.