I’m serious! Do it please.
It suppresses the release of cortisol and boosts the release of oxytocin and serotonin in your body.
Those hormonal changes lower one’s stress levels significantly and keep one vivacious, active and tension free (To a considerable extent).
And, one does not have to have a reason to do it. You can do it anytime, anywhere for no reason at all. Ergo, do yourself a favour and just smile as much as you can, every day, and every hour. Don’t wait for a reason. Just do it.