on (one's) pat

Without or not near to anyone else; on one's own; all alone. Shortened from the Australian rhyming slang "on one's Pat Malone," referring to a ballad about an Irishman called Pat Malone, who suffered numerous misfortunes after emigrating to Australia. Primarily heard in Australia. To be quite honest, after a hectic week of work, I much prefer having a drink on my pat than being around a bunch of people. Mary's been on her pat ever since Rupert broke up with her last week.

on your pat

on your own. Australian informal

This expression is from rhyming slang, Pat Malone meaning ‘alone’.