You may act super goofy and lighthearted around your best friend, but you’re quiet at big parties and kind of a grumpy micromanager when your brother’s kids come over and ransack your personal space. You can be blue-jeans tomboy or elegant lady dressed to kill or sentimental ’80s sitcom fan, depending on the context. You wear many hats, changing them to adapt to the occasion and to your environment.

You might not imagine that your little buddy—drooling on the couch over your bowl of ice cream—can relate, but he most definitely can. His actions, just like yours, are highly contextual. Moment to moment, your behavior changes (often unconsciously) in response to the world and conditions around you. Your environment is constantly prompting you to respond to various demands. You are a chameleon in an ever-changing landscape because you have to be—and so is he. You have both learned to change in order to fit in, get along, and be successful. Neither of you is immune to the world around you. In fact, the world has a lot to do with how you behave. It should be pretty obvious that no one is an island. But sometimes we forget that.

A relationship may shatter when one partner—who fell in love with the attractive and apparently organized coworker previously seen only in boardrooms and fancy restaurants—turns out to be a total slob in his own home. Seeing how your boyfriend behaves at a bar, in contrast to cross-examining a witness in court, can be eye-opening. Similarly, it may be horrifying to watch your sweet beagle kill a baby rabbit when you take him to visit your uncle’s farm. It’s confusing, too; you know him only as the gentle dog who snuggles with cats. When we suddenly encounter a side of our companion (person or animal) that we haven’t seen before, we may lament and panic. We make accusations and jump to conclusions. We say things like, “You’re different. You’ve changed. You’re not who I thought you were.” Somehow we expect the people and pets around us to be static and predictable in all situations, even though we ourselves are not. We forget to consider the environmental circumstances behind others’ changes in behavior.