I may be the last to discover this nifty site feature; my apologies if it’s already been discussed.
I’ve seen for some times the “suggested topics” section at the end of current threads. After a while, I noticed that the threads were of interest to me. Still later, I noticed that at least some of them were ones that I had posted in. I remarked to myself on how clever the site is.
I just noticed today that (not sure) the suggested threads are those that I have posted in, but not finished reading! Appropriately, no suggested thread is presented as grey. On the XK Engine list now, I clicked on a couple and both had responses to my posts that I hadn’t seen. I had lost track, or the post came days after mine. Very cool!