"Should've Known Better" is a hit song written, composed, and performed by American rock singer Richard Marx, who released in September 1987 as the second single from his self-titled debut album. The song peaked at number three on the US Billboard Hot 100 as well as #7 on the Billboard Mainstream Rock Tracks chart in 1987. Marx became the first solo artist in recording history to reach the top three of the Billboard Hot 100 with four singles from a debut album. In the lyrics, the speaker is still in love with an ex-lover and tortured by it, to the point of regretting falling in love with them.