Todd Rundgren did a song where he said "peace breaks out in the battle of the sexes...we start to learn what the other one expects is. we stay away from what the other one rejects is, and have respect for individual perspectives" To me that pretty much sums up training. As a slave, i have an INTENSE need to understand what my Grand Master wants, what He doesn't, what would please Him and cause Him to beam with pride when He thinks of me, what things would disappoint Him...i want to know about His personal tastes...what kinds of things could i do to surprise Him that He would enjoy the most? What is the best approach when i am feeling nervous or when i have really bad news or when He's in a bad mood or whatever...i mean there are so many things...
Everyone trains in relationships, they just may not call it that. In vanilla relationships, there is training too. i mean, you want to learn all about the person you're interested in so that you can have a better perspective of that person's mindset so that things go more smoothly. That's a form of training.
Like others in this thread have said, training is defined differently by each individual. But i believe that a broad, general definition of training would be to better learn the person with whom you have a relationship with the intent to foster and grow a more healthy unity with him/her. If you look at it like that, then how can you really have a relationship without training? i mean you gotta foster it somehow. Communication requires training; you need to figure out the best way to approach someone, and this is usually tailored to fit their personality. How can you know what the best way to communicate is if you don't figure it out? And isn't figuring it out self-training? Like denuseri said, we all train ourselves in a way. Maybe we don't realize that's what we're doing, because we just call it 'socializing', but even in the most mundane of circumstances, if there is a relationship, there is training. i just don't see how it would be possible to have a relationship that works without stopping to figure out the other person and how best to relate to him/her.
The only difference between that and slave training is that there is more variety, and this is where things become much less definitive and much more arbitrary.