Scotch with 2 drops of water

A lady goes to the bar on a cruise ship and orders a
Scotch with two drops of water. As the
bartender gives her the drink she says, 'I'm on
this cruise to celebrate my 80th birthday and it's
today.'

The bartender says, 'Well, since
it's your birthday, I'll buy you a drink. This
one is on me.'
As the woman finishes
her drink, the woman to her right says, 'I would
like to buy you a drink, too.'

The old woman
says, 'Thank you. Bartender, I want another Scotch
with two drops of
water..'

'Coming up,' says the
bartender.
As she finishes that drink, the man to her left says, 'I would like to
buy you one, too.'

The old woman says, 'Thank you. I'll have another Scotch with two drops of
water.'

'Coming right up,' the bartender
says. As he gives her the drink, he says,
'Ma'am, I'm dying of curiosity. Why the
Scotch with only two drops of water?'

The old woman replies, 'Sonny, when you're my age, you've
learned how to hold your liquor. Holding your
water, however, is a whole other issue.'