"The most common interpretation of the phrase is as an existential cautionary term with emphasis on making the most of current opportunities because life is short and time is fleeting. It is thematically related to several other expressions and phrases."
This is from Wikipedia. (The best thing since sliced white bread.)
This picture represents one of the many ways my children and I operate when we are absent from my husband who does not subscribe to the same philosophy. We have been known to pull over to pick all manner of flowers, pick some blackberries and at least once-rescue a large black puppy in the middle of the road. As we were leaving the blueberry picking place, we noticed again these swings. As I like to live vicariously on occasion- I pulled over and let them take a ride on a tire swing. It only took a moment. I hope my children remember the cool things I did more than my not-so-cool moments.
Lord, help me seize the day almost as often as my children hope I will!