How often do you stop to observe the flow of time? Not often, right?
Usually, we only do it as part of a big life event such as someone dying, our kids passing into adulthood, or a new generation being born. We look back on life during those moments and reflect on the flow of time — or rather the effects of it.
It's healthy for us, because it puts life in perspective. We see ourselves from the outside for a while, and it forces us to recognize that in the big picture, we don't really matter; which again forces us to find meaning in the life we have and make the most of it.