when you are happy-smile,
It can uplift you
feel good  about yourself
and have  a wonderful smile

look happy
see your friends
greet them with a smile
you will not loose anything

It only shows that you are happy
and feel good about yourself
a person who does not smile
something is wrong with their personality

he or she is lonely
start a conversation
you may be able to help them
we are not all perfect
share your love with them
they can also change