[Haskell-beginners] Prelude Implementation of Last overlapping patterns?

The standard Prelude implementation of 'last' is as follows \begin{code} last :: [a] -> a last [x] = x last (_:xs) = last xs last [] = error "Prelude.last: empty list" \end{code} Isn't [x] equivalent to (x:[]) hence wouldn't [1] match both [x] and (_:xs)? If that's the case then we would have last [1] == 1 and last [1] == last [] but that doesn't happen. Why?