This song makes me smile literally every time I hear it. It's a minute and half of pure joy. Really, it's 45 seconds of joy repeated twice. Lyrically, it's somewhat beautiful - about quick, pure and true love. It is as hyper and energetic as the actual emotions. Truly, this song is a short masterpiece.
And if you aren't smiling at a LEGO-mation video, then I don't know if I can help you.