That's exactly the way you read; Just smile! All the time!
It should come as no surprise that modern science found out that simply smiling is already a means of attaining happiness. And, of course, this discovery has its roots in Judaism. As our sages say in the Talmud, service to Hashem should be made in happiness. As long as you are not mourning for someone, we should always be joyous for the opportunity of serving the One True Living G-D, wherever and whenever we go. There's always room for divine service. Ergo: We should be happy all the time!
I heard a very interesting Dvar Torah by a rabbi who told me the following equation was "set down" by scientists (probably gotten from our sages also):
happiness = faith + purpose + emotional support
Interestingly enough, he said, we call Sukkot Zeman Simchatenu because we "live" in a very "flimsy" tent, and therefore we are filled with faith that we are more secure there than in our houses (because Hashem said so, surely it's for the best). We also have the knowledge that what we are doing has purpose (it's a mitzvah! we are fixing the world and ourselves!) and we have friends all around us for lechayim and sharing the joy. There's no room for sadness during Sukkot!
The challenge is obvious now. We are not always able to devote our true selves when praying, to be extatic, and to fully understand the loftiness of our mission. We also don't celebrate Sukkot except 7 days each year. The situation is much more aggravated when Pgam HaBrit happens. We begin to feel deppressed and ashamed.
Yet, somehow, smiling has a deep and positive impact on a person's wellbeing.
Quoting a psychology site:
"Smile to relieve stress. Stress is easily shown in our faces. Smiling prevents people from looking too tired or overwhelmed. When you're stressed, try to put on a smile, as it will make you feel happy, and you will appear happy. Your feelings on stress will be reduced as the endorphins associated with the smile are released, and the infectiousness of your smile will help to make others happy. When others are happy, you will feel even happier knowing you're helping others to feel better. You may even start laughing, and if so, others might join in. That shows you that from being sad, you can start laughing with the help of a smile."
[...]
"A simple test to show you how smiling keeps you positive is to smile. Then you need to try to think of something negative, but keep the smile, otherwise the test won't work. You will soon see that it is hard to combine the negative thought with the smile! When we smile, our body and mind are sending us a message that everything is okay, and that life is great. Smiling will help to lift depression and sadness, and with frequent use, works better than any type of medication to relieve you of stress. Dozens of studies show that if you are positive, you are more likely to live longer, a state of being that also helps to ward off sickness."
Eventually, smiling has the same effects of releasing. But smiling helps bring true happiness. Even if it's fake (for the time being)!
Of course, we still need Torah and determination to fight the yetzer harah, because it only gets stronger as we progress spiritually, but remember:
Where there's happiness, the forces of impurity cannot get in!
This is why, the cemitery is such an impure place, and why these same impure forces are diminished on Shabbat and Yamim Tovim.
The message is: when we are smiling, we are less prone to fall and do averot!
Finally, people who often smile live on average 7 more years than non-smilers! That's 7 more years of mitzvot and happiness here!
