I saw this sign in a winery once, but they were advertising espressos & puppies! I thought it was a funny and clever way to kindly ask parents to keep a really good eye on their children and take them home if they're having a hard time behaving.
I like this because sometimes people who work really hard can be easily agitated, quick to judge, short-tempered and stuck in their own little world. It's one thing to love what you do, but don't let it become your identity. Be aware of others around you.