Sipo walks into a bar in Pretoria, orders three pints of Black Label and
sits in the back of the room, drinking a sip out of each one in turn.

When he finished all three, he comes back to the bar and orders three more.

The bartender says to him, "You know, a pint goes flat after I draw it; it
would taste better if you bought one at a time."  Sipo  replies, "Well, you
see, I have two friends. One is in Polokwane, the other in Lebowakgomo, and
I'm here in Pretoria. When I left home, we promised that we'd drink this way
to remember the days we all drank together." The bartender admits that this
is a nice custom, and leaves it there.

Sipo  becomes a regular in the bar and always drinks the same way: he orders
three pints and drinks the three pints by taking drinks from each of them in
turn.

One day, he comes in and orders two pints. All the other regulars in the bar
notice and fall silent.
When he comes back to the bar for the second round, the bartender says, "I
don't want to intrude on your grief, but I wanted to offer my condolences on
your great loss."

Sipo  looks confused for a moment, then a lights dawn in his eye and he
laughs. "Oh, no," he says, "Everyone is fine. It's me..."
 "...I've quit drinking!"