recently during the past couple of months i've been smiling or laughing for no reason and it always came from the inside (a smile or a bubbeling laugh from the inside.)
i've read in some Tai chi books (Mantak Chia comes to mind) that this is supposed to be a practice "Inner smiling" but the funny thing is that it isn't intentional it just happens when awareness kicks in or when i practice mindfulness and recently a lot of the times during AYP Deep meditation...
When hair stands on roots, you laugh or weep without your wishing, you are filled with fear or see frightening visions, semen passes out involuntarily, know that the kundalini shakti has become active.
Welcome to the club, Ananda! I'm also smiling A LOT these days... With a grumpy mind trying to get the mouth to stop that silly grin... Luckily without success!