These actors are in their 70's!

Bill Bryson was 44 years old in 1996, the year he hiked the trail. His friend Katz, a school friend, would have been about the same age, and his wife is also roughly in his age category. Robert Redford is now 78, Nick Nolte 73 and Emma Thompson 55. She's the only one within hailing distance (a decade or so) of the real person she's portraying.

It's not just a question of Redford being 30 years older than the man he's playing. When he took off to hike the trail, Bryson left behind not only his English wife, who was still adjusting to life in a new country (and struggling with mastering driving on on the right), but also four children, ranging in age from early elementary school up through late high school. There was an underlying sense of connection to a young family in the book; he thought about them, missed them, and broke off the hike at various points to go home and see them.

A man in his late 70s rarely has the sense of responsibility for raising a family that he had when he was the father of a growing family who needed him. I suggest you read Notes From a Big Country, a book of newspaper columns that he wrote during the mid-to-late 90s for a British newspaper. His family are a regular feature -- taking his eldest son off to university, attending Dartmouth basketball games with a daughter, playing catch with his youngest son, seven-year-old Sam, on the lawn. By his 70s most men are grandfathers, the day-to-day routine of child-rearing a distant memory. In retirement, they have the time and freedom to tackle a long-term challenge that is much harder in the prime working years. Portraying Bryson as a man in his 70s will inevitably change the tone of the story.

Men in their mid-40s tackling a physical challenge like through-hiking the AT are often motivated by a desire to show that they haven't lost their youth, that they're still fit enough to succeed. A man in his late '70s has no such illusions. He's not twenty again or anything close to it. He's more likely to be motivated by a desire to complete the hike while his body is still able to, but there's no question of clinging to eternal youth.