But just like the countries you also have your own personal currency - your smile.
I know you are counting on me to elaborate, and I won't disappoint you. :D
As any economist will tell you, it is not good for the economy if people hoard the currency. The more people spend the currency the better for the economy. Same thing applies to your smile, it does you no good to keep it in, it's always better if you distribute the smiles all around you. You are the walking talking ATM for this currency.
Not all currencies are the same and the same currency is not the same all the time. When you smile without really feeling it, it's like the currency that was devalued after last night's coup de etat. When you smile at seeing a loved one, it's like your country just elected a new president!
When a receptionist smiles at you, that's like she's handing you play money used by drama companies. It's printed on glossy paper and the colours are bright but it's not real money.
Then there was the shayar who said,
मेरी रूह की हकीकत मेरे आंसुओं से पूछो,
मेरा मजलिसी तबस्सुम मेरा तर्जुमा नहीं है.
(The truth of my soul you will find in my tears,
my public smile is not my reality.)
Obviously, he was passing on a counterfeit currency.
Now, some people think that this is a gold-backed currency. Meaning that if you have money and material comforts, you are happy, and when you are happy, you smile. That's not entirely true. This is in fact a fiat currency. You can keep passing on as many as you like without the value going down at all. It has been scientifically researched and established that if you smile it makes you a little happier than you were before, EVEN IF the smile had absolutely no valid reason behind it.
I dare you, try it right now, you just CANNOT think sad thoughts while your lips are curled in a smile, even when without any reason at all!
Just like the other currency the smile is also traded, exchanged and spent. Sometimes when you spend a smile you get a smile in return. This is foreign exchange. Now, unlike the other currency this is a PROFITABLE trade, for BOTH parties! Yes, this currency has its own rules of exchange.
Sometimes you spend a smile but don't get anything in return. This shows you invested in a dud economy. But according to the smile-economy laws, you don't lose anything in this trade. Giving it away for free is the MOST PROFITABLE trade in this currency.
By these rules, when you have no money, you are not broke. But if you have no smile to give another human, you are bankrupt!
So, keep smiling, it raises your face value!