I can't say it better than Buzz Aldrin, but I can add this:
I am a member of the "Sputnik" generation: I was in elementary school during the Mercury and Gemini programs, and Neil and Buzz walked on the moon before I was a sophomore in high school. I dreamed that I could aspire to be on the first manned mission to Mars.
Now I wonder if this will happen in my lifetime; or ever. This is a damned shame, and may mean that we're squandering mankind's best chance for an almost infinite legacy, as opposed to following the dinosaurs into oblivion.
Some people bemoan the cost, and I have thoughts on that I will share at another time; for now, please just pay heed to Buzz's aspirational message.