Percy says "the best people get the rottenest luck." How does this apply to his mom?

In this quote, Percy is referring to his mother. Percy considers his mother the best..... but that didn't stop her from falling in love with Poseidon and having his child, only to be left raising him alone. We also learn that Percy's mother makes a bad marriage in order to hide Percy's parentage..... to keep him safe. In the end, we learn she's been kidnapped by Hades..... quite the adventure and quite the bad luck.