know whether one is Arthur or Martha

verb1

•
(Australia, informal) To be in a clear state of mind.
- His impression was that practically everyone at the party had been drinking on the night in question, and 'wouldn't have known whether they were Arthur or Martha. — 2007

forms

knew whether one was Arthur or Martha · known whether one was Arthur or Martha · knowing whether one is Arthur or Martha · knows whether one is Arthur or Martha