Sometimes we think a lot about what we're going to write, and even though the post isn't long, if it's been a while with no activity since logging in, we'll get timed out. So-o-o-o...
Whenever you login, be sure to check the box next to where it says "Remember me." Then, no matter how long it takes to write a post, you won't be timed out!
Yes, and (depending on your browser, maybe) you can usually go back to what you wrote when you use the "Back" button.