White spirit
A man dressed in a painters overalls walks into a hardware store and asks for a bottle of white spirit. The proprietor looks at him. "No. You're that alcoholic bum who used to always hang around the village green - you'll just drink this." The man is shocked: - "Oh no, you are mistaken - I used to be that man, but I have a home now, have started up my own painting and decorating business, have given up drinking, and cleaned up my life entirely. I need the white spirit to clean my brushes, or they'll be ruined. Why is is that nobody can recognise me for the person I want to be, rather than the person I used to be?" The hardware proprietor pauses to think. "You're right, I'm sorry for judging you based on your past. Would you like a litre?"
"Thank you! Yes, a litre bottle. Do you have a cold one?"