They Say What They Say

I want to see Esther because she's bound to be a great person

Absolutely. She'd be the only person in the world who could tell Isaac that he's being an old fool and not only get away with it, but have him take note of what she's saying.

But we know nothing about Sam, because Dan is the most unreliable narrator ever in that area. All we know is how Dan sees Sam now, through the lens of years and death and guilt, and that's just - Sam could have been anyone.

Like a lot of people who have lost someone close to them, Dan possibly has this idealised view of Sam and his life, when in actual fact he could have been one of the most obnoxious, annoying teenagers on the planet, even more so with him being so intelligent. Sure he died the day he got his licence, but maybe it wasn't the first time Sam had gone driving on drink and drugs. Maybe it was the culmination of him doing everything and anything he could to rebel, and in his grief all Dan chooses to focus on is how Sam wouldn't have done any of it if he hadn't been such a poor role model.