Why is bittersweet a paradox?

Bittersweet is an oxymoron, which is a Word where it contradicts itself. (Other examples include stupid genius, peaceful war, sharp dull, living dead, dark light).

This coincides with the definition of a paradox, which is something that is a seemingly absurd and self-contradictory statement. Therefore, an oxymoron is a paradox, which means bittersweet is a paradox.