Use a colon instead of a semicolon between two strong clauses (sentences) when the second clause explains or illustrates the first clause and no coordinating conjunction is being used to connect the clauses. Capitalization of the sentence following the colon is optional.
Examples I enjoy reading: novels by Kurt Vonnegut are among my favorites.
Garlic is used in Italian cooking: it greatly enhances the flavor of pasta dishes.
No kidding.......daaaaaaaaaayum!