You're just running into the fact that people often spurt jargon as a shorthand because they're trying to quickly get a point across to other people who have encountered the same jargon before. Everyone in the industry knows that it takes a long time to actually learn anything non-trivial to a deep level, and everyone knows that everyone has their strengths and weaknesses.
So, I see (and remember) how it seems forbidding, but I also see that you're being too hard on yourself, relative to what anyone will ever actually expect you to know. You will pick stuff up and make things happen when you need to. Until then, just ride the waves of jargon with slow inscrutable nodding.
If you're after specifics, I found I understood bridging a bit better after I decided to build a router from scratch. My router at home is just a linux box with a 4-port NIC (network interface card), and the ports on the card are bridged to make it easier to route and firewall them. I had to use a bridge, so I learned the command to make a bridge, suddenly I'm the bridging expert because no one else dogfoods this kind of crap, get it?