I think comments of this sort actually express a deeper desire that we all have to feel such confidence and contentment in our lives that we are able to take in stride these fleeting peaks and valleys of living. To me this means being able to experience the purity of a happy moment without grasping at it to try to make it last longer than it's natural life. And it means being able to experience our sadness (or other less pleasant emotions) without the fear that it (they) will overwhelm and consume us. We can have this experience when the spirit part of our mind-body-spirit relationship is taking the lead over our emotion in our experience of life. Or to put it another way, when our spiritual ground of being is strong, our emotions can be seen with reasonable perspective.
We are actually born with this solid ground of being. All one needs to do is to imagine a child asleep in your arms to understand that. A child goes through emotions "like green corn goes through the new maid" (as we say in New England), but they seem to be able to return with ease to a place where the concerns of emotional turmoil are set aside, and calm prevails.
Now the trouble is, if you are reading this you are not a child. All the same, that same state of calm still exists within you. We will not find it by trying to return to the elusive "inner child." Rather, it is invoking the almost equally elusive "inner adult" ( as my friend Ashley Davis-Bush would say) that will give us access to a solid ground of being. In children, it happens automatically. In us adults, it is a choice--a choice that takes practice--but a choice none-the-less. We can't get there by merely trying to eliminate our emotions.
This is where a firm foundation in spiritual practice comes in. Spiritual practice does not necessarily mean prayer, church, meditation or the like. Spiritual practice is any intentional action which strengthens our connection with, and confidence in, our ground of being. It is anything we do to live more firmly in a solid ground of being so that when happiness or sadness emerge, as they inevitably will, we are still sure that we can enjoy the highs and withstand the lows. So, play music, sing loudly, walk on the beach, meditate, make something, do regularly those things that strengthen your ground of being: it is there that contentment consumes sadness and allows happiness a moment in the sun.