@sailortinkitty, what you say is simply not how it happens. The confirmation email is sent for the specific purpose of verifying that you DO own the address you are trying to create the account with. If you don't respond, the account is never validated.
You don't have to be logged into Yahoo email or any other email to create an account. You just create the account. THEN you sign into your email account to get the confirmation. And no, sorry, but I will not in this lifetime create or use a Yahoo email account. Their security is horrible, they're spam traps, and I refuse to use web based email systems, period. I have my own domain, my own mail server, and I can create all the accounts I care to have, secure on my own server in the closet, thankyouverymuch.
I have created quite a number of YT accounts, never once being logged into the email account I typed into the creation page. When done, and the confirmation mail is sent, I check mail on that account, click the confirmation link, and it's complete. If I should not click that link, within a matter of several hours the account creation is nullified, as if it never happened. I could do this through any ISP, anywhere on the planet, and it would work the same.