You could just trying to read the posts even if you don't explain all the jargon: over time, as you get more exposed to the terms that people use, I'd expect it to get easier to understand what the examples mean. And you might get a rough idea of the main point of a post even if you don't get all the details. Eric Drexler actually argues that if you want to learn a bit of everything, this is the way to do it.

If you don't understand some post at all, you could always ask for a summary in plain English. Many of the posts in the Sequences are old and don't get much traffic, so they might not be the best places to ask, but you could do it an Open Thread... and now that I think of it, I suspect that a lot of others are in the same position as you. So I created a new thread for asking for such explanations, to encourage people to ask! Here it is.