Refers generally to
cannabis-
based therapy but could also refer to other psychedelics, or more broadly to embracing nonchalance. Pending context, the expression could be an invitation to others to partake in an activity, or a declaration of indifference to
one's carefree decision making. The expression is generally used without punctuation, similar to Marvin Gaye's 'What's Going On', and is also seen abbreviated to WNM.