Would a Buddhist take him or herself too seriously? Probably not, and just as you can find beauty and love in anything, everything, and everywhere, you might find deep Buddhism in the most unusual places.
There’s something about the concept behind "Even if the world was to end tomorrow, I would still plant a tree today", is it the selfishless pursuit of something greater than you and of today, rooted in the now, a start, with a life and a journey of its own, and whose benefits will be enjoyed by many. Maybe the world would only come to an end only for us humans, if so your tree will allows birds to nest on its branches, deers to seek relief from the sun in its shadow, squirrels to find food. What is the tree that you plant today in spite of you not enjoying its benefits? What does the tree represents to you today, and to others tomorrow?
A tree is only the metaphor for what is in your mind, yet out of consciousness, and if you look with the corner of your eyes, down in the ally that you pass by every day without stopping, you might find a glimpse of your tree, and indicator of something you can do today, that will benefit someone else tomorrow, even though the world might come to an end.
If the world were to come to and end tomorrow, would you still mow your lawn?
Rake those leaves?
Hold a grudge with a loved one?
What is that is keeping you busy today, and make you postpone something else till next week or next month or next year?