: He was struck by the natural simplicity of the act. While humans have complex emotional hurdles regarding sex, the animals simply "did it" without inhibition.
: Paul witnessed two monkeys mating in the middle of a road. Why Don't We Do It In The Road? (Remastered 2009)
Despite being a Beatles track, it is essentially a solo effort by McCartney, with only one other band member involved. Why Don't We Do It In The Road? (Remastered 2009) : He was struck by the natural simplicity of the act