Sampol! Sampol!

Why do people instinctively shout "Sampol! Sampol!" Whenever somebody mentions that he or she loves to sing (or dance, for that matter)?

Are these Sampol-people really, truly, genuinely interested in listening, or is it just a default statement, a part of the script that needs to be uttered? Or do they fully intend to watch the "victim" turn red?

The next time we catch ourselves shouting "sampol!", let's mentally evaluate our intentions, shall we? =)