from OED:
adjective
'In plural form bananas. Chiefly in predicative use.
1929–
colloquial. Originally: lacking reason or common sense; very foolish, irrational, or erratic...'

But 'going bananas' also invokes playfulness and celebration as in a parade or a festival.
Physical comedy dates back to ancient times with gags such as slipping on a banana being very popular during the Vaudeville era. This 'banana' act was first used on screen by Charlie Chaplin in the movie 'By The Sea' (1915).
Humour allows us to cope with stress and to thrive emotionally. It allows us to connect and maintain relationships and to deal with adversity.
I am serious about my mark-making and devoted to being playful.