Dean and Sam did find out about John Winchester's deal with the demon to save Dean in season four.
Sam Winchester was born on May 2, 1983 so he would be 30 years old today.
As of the 2014 MLB season, Sam Dyson is 26 years old.
As of the 2014 MLB season, Sam Freeman is 27 years old.
As of the 2014 MLB season, Sam LeCure is 30 years old.
As of the end of the 2013-2014 NFL season Sam Longo is -- years old.
As of the end of the 2013-2014 NFL season Sam Montgomery is 24 years old.
As of the end of the 2013-2014 NFL season Sam Martin is 24 years old.
As of the end of the 2013-2014 NFL season Sam Barrington is 23 years old.
As of the end of the 2013-2014 NFL season Sam McGuffie is 24 years old.
In Season 2, he is 23, but as the seasons go on he gets older, so by Season 5, he is 26.
Sam Michael is 40 years old (birthdate: April 29, 1971).