This is actually one of the most interesting analogy anyone has ever used for bitcoin. It simply captures the whole essence of bitcoin in just thress sentences.
Just like the best time to plant a tree is 10 years ago, the best time to buy bitcoin is also like 10 years ago when bitcoin was still very low in bitcoin. If one had bought some 10 years ago, then one would be rich by now just by hodling.
And just the second best time to plant a tree is today, so it is for bitcoin.  The second best time to buy is today. Irrespective of the price of bitcoin today, it still has the tendency to grow even more higher. Take a sneak peek into the future and imagine what the price of bitcoin would be 10 years from what it is today.