Sorry if I made it sound like I’m projecting what your needs should be. What I was trying to say, and I still believe is true, is that if you think of a “topic” as the main unit of discussion, and replies flowing “down” in this discussion, then taking you to the first unread reply when clicking on a topic lets you resume catching up.
Losing your place in discussion assumes you’re scrolling up, I guess to refresh your flow within the topic, or clicking through quotes to get to the source. That makes perfect sense to me. There is functionality to help you get back to the reply you were originally looking at (see the “Back” button):
Surprisingly, I don’t see it consistently appear, at least not on Firefox 
I guess this is a bug we should report.
Now, a more general note.
It’s been less than two days since the introduction of Discourse. In this time you posted 14 times, sometimes using rather loaded language like I quoted above. Both the volume and the language undermine what you’re trying to communicate. Nobody is ignoring you, Paul, and I am confused by your claim that you’re not getting good answers when you thanked for helpful explanations in that very same thread above.
It’s natural to find things confusing for a while, I know the feel of losing your place, not knowing what a given notification wants from you, and so on. This is why @dstufft and I try in this thread to both explain how Discourse works and suggest you give it a few days. The point with this suggestion isn’t to shoot your concerns down. The point is to acknowledge that this new tool is necessarily different and some things might take a while to get used to. If your concerns persist and you come back after a few weeks saying “this thing is a critical loss of functionality to me”, then that will hold more weight than a set of what appears to be emotional reactions posted within the first day of using the tool.
To take this back on track: it looks like we identified a bug in the timeline functionality designed to help alleviate your valid concern around losing your place when scanning a discussion with new replies. This is helpful, we’ll report it and get it fixed. And in general, taking the Discourse test so seriously is helpful, thank you for that.