I noticed another factor in this sorting business. Now that I have it sorted out here to my liking, I may also choose to get an email about new posts to topics I want to follow. That email contains a link to take me directly to that topic, but of course, at that point I am not logged in, so the new post on the topic, will, once again, be found at the very bottom of all the previous emails rather than the top where it would be useful.
I will have to have another look at the user control section and see if there is a setting to log me in automatically when I follow the link in those emails.
Dave