In the world of a behaviourist, the ABC's mean more than just the letters of the alphabet. They represent the relationship as part of one's behaviour(s): the (A)ntecedent-(B)ehaviour-(C)onsequence chain that is most of the behaviours we demonstrate. To keep things simple, antecedents are things that happen before a noted behaviour. You can call them "triggers" or "cues" if you'd like. For example, for many of us on the roads, the traffic light is one antecedent to our driving behaviour. If it's green, we go. If it's red, we stop. Meanwhile, consequences are the events or responses that occur after a behaviour. These are either reinforcing (therefore behaviour maintains or increases over time) or they are punishing (therefore, behaviour decreases). In the traffic light example, attending to the red light and putting on the breaks results in us safely stopping in time; thus, preventing any harm or accident. For the most part, going through repeated experiences of the same A-B-C chain results in us learning and maintaining our skills.
Imagine all the A-B-C chains you go through on any given day. Now imagine your role as part of someone else's A-B-C chain (i.e. something you said or did is the antecedent or consequence of someone else's behaviour). If you're not overwhelmed already, next imagine all the different people in your life and the lives of others fulfilling the same antecedents/consequences but under different circumstances or in different environments. The combinations of A-B-C chains seems almost endless. The Count can't even keep up!
With so many varied and possible A-B-C chains, it explains how we as humans are unique: each with our own set of behaviours, skills, talents, interests and yes, even challenges. We all have our own unique learning history that sets us and our behaviour apart from others. Human behaviour is unique. We are not all robots, nor does behaviourist theory attempt to make a person into one. Unfortunately, this is an ever-returning criticism of behaviourism: that it ignores individual uniqueness. I did fairly well in my finite mathematics course in high school and so I'm certain that the rate at which someone will find their perfect behavioural match is an unthinkable number.
Perhaps The Count will let us know when he gets to that magic number 1 in ??????