have you ever heard someone say 'smile, it makes people wonder what you are thinking'?
Often it's the smile that gives the spark for happy thoughts not just for you but for those around you. yes, people may wonder what you are thinking but that's secondary, it's enough to see smiling faces, to believe that people are happy and to rejoice in that.
Smile at everyone you make eye contact with today and if you feel up to it, try this little amusement that I use to amuse myself whilst out driving. Wave at people as if you know them, see how many people wave back. They either think they should know you or they appreciate a friendly gesture. The thing is nearly everyone appreciates some light positive attention so you are doing your bit to make the world a smilier place.