What is Gratiano's philosophy to overcome sadness?

Gratiano is telling Antonio to "chill out" and have some fun. He says it is better to get laugh lines all over his face than wrinkles from worrying. He would rather overload his liver with alcohol that deny himself a good time:

With mirth and laughter let old wrinkles come.
And let my liver rather heat with wine
Than my heart cool with mortifying groans.

What was Gratiano’s philosophy to overcome sadness?