Random: I Think I Love You

For some strange reason I've had some odd music stuck in my head lately.  Last night it was Christopher Cross' 'Arthur's Theme'.  Which, let's be honest, is an awesome song, and it doesn't even have to be 1981.
Today I've had The Partridge Family's 'I Think I Love You' stuck in my head.  I don't know who gets credit for the song actually.  Is it while whole Partridge family or just David Cassidy?  I couldn't answer that question, as I've never actually seen one episode of The Partridge Family.
Maybe even more strange, I don't know where I've ever hear this song.  I don't even know any lyrics beyond "I think I love you / so what are you so afraid of?".  Are those the lyrics?  I don't know, but that's what I've been singing.
How about you? What song has been stuck in your head lately?