I'm not sure about the interface your using but if your on the main forums page there is a link that says "you active threads" and that will show that date of the last post to threads your involved in, not sure if that helps you or not.

Otherwise, I'm afraid you'll just have to get used to how the forum works compared to others.  A lot of posts in the past about this and similar requests to a format change.  You can search them and see the response, but that leads to another forum quirk.  The search feature only goes back a year, using google to search the site directly is the only way to search older post.