The More I See The More I do

I asked my boss if he would mind if I left the office early on Friday  - and he said no problem. 

I headed back downstairs, text himself and told him when to pick me up and set about finishing my work. 

When my boss appeared an hour and a half later, he said "why are you still here....."

and I said, "i asked to leave early.... not that early". 

But next time I'll know.