The opposite to being off your face
- being a responsible person who isn't intoxicated and doesn't endeavor/manage to somehow detach themselves from their complexion. If you are this, then you are on your face.
'I watched a documentary on BBC2 last night and ate some biscuits, I was completely on my face.'
'I'm going to get completely on my face tonight. Perhaps I'll read a book.'
'I was perfectly aware of getting home last night - I must have been completely on my face!'
'You look very normal, you must be on your face.'