An Irish Family Tradition

An Irish Family Tradition 

Paddy, had long heard the stories of an amazing family tradition.

It seems that his father, grandfather and great-grandfather had all been
able to walk on water on their 18th birthday.
On that special day, they'd each walked across the lake to the pub on the
far side for their first legal drink.
So when Paddy's, 18th birthday came 'round, he and his pal Mick, took a boat
out to the middle of the lake, Paddy, stepped out of the boat ...and nearly
drowned!
Mick just barely managed to pull him to safety.
Furious and confused, Paddy, went to see his grandmother.
'Granny,' he asked, "It's me 18th birthday, so why can't I walk 'cross the
lake like me fa, his fa, and his fa before him?" 

Granny looked deeply into Paddy's, troubled brown eyes and said, "Because
your fa, your grandfa and your great grandfa were all born in December,
when the lake is frozen, and you were born in August, ya dip shit.