"Only those who attempt the absurd will achieve the impossible."
The grandest of callings often seem impossible or ridiculous. Which means that if we choose to pursue them we run the risk of looking silly. People might criticize us. They might challenge us. They might even chuckle at us behind our backs.
I suspect Walt Disney, Mother Teresa, Martin Luther King, Moses, Jesus Christ, Bill Gates, Jack Welch, Thomas Edison, Albert Einstein and many others like them have felt the same way at some point during their lives.
Let's put it this way, when faced with an opportunity to do something that seems impossible, do it anyway. You will be in good company.