Because you failed to revalidate your rating before it expired. Once it epxires the only option open to you is to renew it, irrespective of how many hours you may have flown in the previous 12 months.
Absolutely correct.
Because you met the requirements to revalidate your class rating on the basis of experience you COULD have simply found an examiner and got him to check your logbook and sign your Certificate of Revalidation, eliminating the need for a flight with an examiner - but this is no longer possible because your rating has expired.