Theologian and Bishop Jeremy Taylor bears these thoughts,

Enjoy the blessings of this day, if God sends them; and the evils of it bear patiently and sweetly: for this day only is ours, we are dead to yesterday, and we are not yet born to the morrow.

This passage reminds me to seize the moment and not squander it with worries, doubts or concerns. The day is given as a gift, just as yesterday was. Yesterday's wrappings are now old and the surprise inside unveiled. Why look towards tomorrow, when we've barely begun unwrapping today's. A 'thank you' should be said.