There's always a lil truth every behind "Just kidding".
A little knowledge every behind "I don't know".
A little pain every behind "Its okay".
A little emotion every behind "I don't even care".

So, when we're talking about something jokes, a lil bit about 'a feeling' and everytime u say "nope, just kidding" it means there's a lil "truth" inside it, isn't it?