I don't know what your definition of codependent is. Everyone needs other people, there's nothing unhealthy about that. Love has a lot of dependency built in, that's why the marriage ceremony has the "to have and to hold from this day forward, for better or for worse. . ." clauses :-)

It sounds to me that you have a pretty good idea of when someone is being mean/unhealthy, as you demonstrated by being turned off by the guy hitting his horse. Presumably you're not going to let someone abuse you anymore. I don't think true codependency happens in a strange/magical way; it is not something you "keep yourself from" as it depends on you, your personality, the other person and their personality and actions, in real time. Every relationship between two people is different and has to wait until the relationship, can't be planned "ahead." But would be best if you think exactly what you define codependency as and then think of a few red flags for yourself so you'll know if the relationship is going a way you don't like and a couple ways to block those types of actions?