Inbox Zero - gmail [find unread mails]

i used IMAP service using thunderbird and it was interesting to see inbox unread message count 1 (one) even when i had no unread mails , my inbox is always ZERO . Why i am telling this because before using IMAP the count in the browser was zero for the unread. and now it is one even in the browser. I thought it might be soem sync problem and tried to fix it bt relogging. but no fixes ..

found gmail discussion forum useful and got a way to search unread mails using the search field
typed in :

label:inbox is:unread

and found an unread mail, two years old ... i can't believe it , how i skipped that ... now it again

INBOX ZERO