Remember that all the pages (Tiddlers) in this manual are actually part of ONE single web-page, so the "Backwards", "Forwards" and "History" buttons on your BROWSER are of no use to you in a tiddlymanual. (Incidentally, clicking F11, or selecting View > Full Screen to hide the browser and make more room for the manual is a useful trick.)
So, instead of accessing the History via the browser you do it from the the left hand Sidebar, where you will see a panel titled "History": this records and lists the title of each Tiddler you open during a session in the manual.
Think of this as the piece of thread that you unravel as you go into the labyrinth - it can be useful to remember where you have been during a session, and to re-trace your steps or revisit any content you have closed earlier. When you click on any title stored in the history widget, you will re-open that tiddler.

Use SNAPSHOT to remember/share history

When you close the whole manual (or click "refresh" on your browser) the history will be lost, so if you want to share a page or collection of pages that you have opened, use the SNAPSHOT button (in the Currently Open panel, just beneath the History recorder.)