Yes, you are right. If other people have access to the computer/browser that you have used, they can get your login credentials.
I actually came across a situation where this was really possible. I went into an internet cafe and had access to the complete browsing history of the people who had used that computer before me. This was some years ago, browser was an Internet Explorer and all options to erase the history manually were disabled.
When I asked someone of the guys who worked there, if it wouldn't be a really cool idea to give each user something like a fresh session and browser history, he said that this is not a security problem at all, because it is "the same people who come everyday". So it is ok that I can see where they have been? WTF!
