"I've found it! I've found it! A Mountain of Gold."
Big Jim says this once he discovers the mother load of gold on the mountain. This statement speaks to the desire of every person in Alaska. It's a cry of achievement and a better life because of the work that has been done in order to search for and find the gold in life.
"I'm sorry, I must be crazy."
McKay says this after trying to go after The Tramp thinking that he is a chicken that he can eat. His statement speaks to the nature of hunger and how it quite literally can drive someone to be crazy and do crazy things.
"I guess you're lonesome here."
Georgia says this to The Tramp at the cabin where he is staying. Her statement drives to one of the themes of the film which is loneliness. What she says speaks volumes because someone finally sees it and says something about it rather than overlooking it and allowing themselves to not be concerned with another's problems.
