If I'm typing something (this question for example), and I press Home, and the blinking line, letting me know where I'm typing, goes to the front of the line. To go back to the end, I can just press End.
What if I'm editing what I've already written? For example, if I want to bold a word. I first go to that word (using the Ctrl and Arrow keys, then press "**". I then slip, pressing Home.
How can I go back to the last place I was typing before I pressed Home,End, Page Up or Page Down?