Yes ask yourself, have you smiled today? A little smile can surely make you happy or at least lift your burden a little bit.
A simple smile is also a great conversation starter, just by a genuine smile you can start a conversation with total strangers.
But of course help yourself with a good manner when talking to the stranger, as a smile might a starter but a good manner might greatly help you get more connections.
A simple smile will also give you a good favor in asking for help, as your genuine smile will be a sign of how nice you are. Thus making others not reluctant to lend you a hand.
Your genuine smile also can help others release the stress they are facing. It gives them something to cheers on, or a warm and friendly feeling that they need to get through their problem.
Often times I read stories of how one simple smile can really help others get back on their feet after a rough day. Or if you have kids, you will definitely feel that your kid's smile can really erase your long day burden at work