I swear, I know it's normal, but come on. I will ask a normal question in a happy, mommy voice and get a blatant backward answer. Like "Did you have fun seeing John?" and he will answer "I didn't see John". He will grin, so he thinks he is being funny. I will play along sometimes, but most of the time, I just want to have a conversation with him and it frustrates me.
I will ask him to stop touching something, stop climbing on something, please go put your toy away, please do whatever I'm asking, and he pretends he didn't hear me. So I say it nicely. Direct him to do it. Finally, I yell and he does it. Or he makes me do 1-2-3 magic and get all the way to 3 then he will do it.
Gah. I try to explain things nicely. He doens't take it seriously (because he's 4, I know). I try to direct and he doesn't seem to learn.
I am not a spanker, but I can see why people might think it is effective.