I've never entered a beer in a competition. I only bring my homebrew to the club meetings if I feel like it's good enough to stand up against all of the other beers that will be there. I don't share growlers with friends unless I know i nailed it. I've had so much hesitation about sharing beer that it's held me back as a brewer.
I'm working on remedying this. First off, I'm entering two beers into the National Homebrew Competiton. Second off, I'm going to start regularly bringing growlers in to work on Fridays to share with co-workers. I've been bringing in bottles to help clear my cellar a little bit, which has helped expose people to good beer, and now it's time to let them try some of mine.
It's easy to share you first couple of batches, but after a few years (6 for me at this point), you start to expect that you should only share great beer. Breweries dump beer when it's not right, but they have so much more riding on it. My friends will just laugh and enjoy the free beer.