let's say this small example for myself. and i love this idea.
every time i do a favor for someone and get a simple "thank you" , i smile for the rest of the day.
if you don't see a smile on my face,search for the smile that i've got in my heart.
i also smile when i see my dad pass by,when i hear that my cousin is coming to visit me etc..
believe it or not,there IS a reason to smile every day.