Mistakes won't kill you. (Well some of them will. But creative mistakes won't. At least they shouldn't. They better not...)
I've talked about how much I hate when people reply with "I don't know" or "I wasn't sure so I didn't do/say anything."
I've also talked about how important it is to fail and to fail big. (Read: Embrace Your Fear, Fear of Failure, Excuses Make You Look Bad, Fail Big, Dealing With Death)
If you never jump out of the nest, how will you ever learn to fly?
Here are some quotes to reinforce that sentiment, and hopefully encourage you to get creative, go crazy and make mistakes.