Funny you mention that since the first time I heard them sung backwards involved a field sobriety test that the driver passed.

I decided that it was a useful skill. Later when our kids were born and the long early morning hours were filled with rocking chairs noises, diaper changes, feeding and burping I took the opportunity to add that version to my song list. Sometimes I ended up singing every song that I knew any words from so it helped a lot when I was tired to focus on one tune.