Whatever way you handle the situation this part seems simpler to me. Learning more is good. For sure. Despite this, there is a really good chance that he will think that you don't understand. Not in the knowledge part, but in the sort of understanding that only having it can confer. This is something that is unavoidable. Understanding is one thing, living it is another. But that is ok. People with BP (and those with other things of course) know this is the case. It's the caring and acceptance that matters. The very most. And that, you do.