I really wanted to be an astronaut.
Photos like these were a big part of the reason why. #14 is probably my favorite. Click the "full earth" photo to bring up the gallery.
In the theoretical (and completely unworkable) system where you get to allocate your tax funds to whatever project you think is most worthwhile, I throw every penny into space exploration, both manned and probe. Dammit, by now we should have been on Mars, or beyond.
Thanks to Dad for the link.