Lucius Annaeus Seneca

Sometimes the routes leading to feelings of anger are so convoluted and circuitous that it takes enormous skill to discern their original source, or fountainhead. But regardless of the reason for or the source of the anger or the relative ease or complexity in perceiving either the anger or its source - everybody, but everybody, gets angry.

Mostly we're motivated to control ourselves in public. Mostly. At home the motivation is much less clear. At home there's a bit of a lab for bad behavior. You can test things out without terrible consequences. Or maybe the consequences are there, but they are deferred, buried, much harder to detect.