Makes me think about love and how powerful it can be over you, plus the really annoying background music gets into your head and you just can't get it out until you start to think, "hey, I actually like this song"...even if you don't!
There is much that U2 did in their first three albums (Boy, October, War) that have been forgotten by the clout caused by their next three (The Unforgettable Fire, The Joshua Tree, Rattle and Hum). When people say they don't much like U2, it's largely based off of only the singles from War up through Achtung Baby. This song is representative of songs, for even some sincere U2 fans, that have been forgotten injustly. Brilliant structure and chords, somewhat cheesy but ultimately highly forgivable middle section.