The Password Manager won't save a Username alone. Username and password would be saved as Password data, but a Username alone might be saved as "form data". The problem is that saved form data isn't saved relative to a specific domain and you are liable to get a lot of irrelevant data in a drop-down.

Have you tried clicking twice in that Username field to see what autocomplete choices are offered?

Last week I used my laptop at a public library. Since then, when I click on a username field or ID space, my e-mail address does not automatically drop down so that I can click on it rather than having to re-type it in every time. This is very inconvenient. Before I used it at the library, my address would appear every time I clicked on the username space. How do I reverse this?

I'm talking about hotmail and google, where I have accounts.