Attempting to Achieve

This past summer I went to the Crystal Cathedral in Anaheim, California. In one of the buildings, a giant steel quote sat on a white wall that asked: "What dreams would you dream, if you knew you could not fail?"
What would you attempt to achieve if you knew you could not fail?

Dreamers

Please answer the following questions. Make sure to respond off one another; if you feel so inclined, please pose a question for others to ponder.

If you are a dreamer, do you have to be more careful/vigilant? Do the characters in Gatsby have a dream? Is idealism a way for people to escape reality? How might this be true for someone like Jay Gatsby/James Gatz?
Nick says to Gatsby, "You can't repeat the past." Do you believe this is true? Are there repercussions of bringing the past to the present?