The internet is all the proof required to know many, many people cannot reason at the most basic level. The family member who thinks schools need to teach logic in middle school is absolutely right.
I'm a fangirl--it doesn't matter which actor--and there's a woman I see on various fan sites who is certain the actor is gay. She reads between the lines of every print interview in which he mentions a male friend or colleague, gleefully reposts pictures in which he stands near any other handsome actor (while ignoring those of him near or touching gorgeous female actors), knows his few public relationships with women are for publicity's sake, ignores the pregnant girlfriend, and generally sees what she wants to believe whether it's there or not.
Among her favorite arguments to convince others (which seems to be her mission in life) is a novel written by a gay director who has worked with the actor. A character in that novel is very probably based on the actor, and that character is gay and has sex with the narrator. Obviously the director had sex with the actor, right? Is this not proof?
This is where her logic fails.
Novelists, including this director, put themselves into their characters. There's a bit of me in everyone I write, male and female, hero and villain, gay and straight and in between. I'm the curvacious wife--and her neglectful husband, the new lover, the older woman who becomes a friend, the elderly neighbor headed for a nursing home, the harried doctor, the stuttering man who prays aloud, and the cop.
Writers add many details which are not drawn from their own lives. They're inventions, fantasies, what-ifs, intended to develop the character or propel the plot.
Do I fret over my looks like Natalie? Yes. Am I long and happily married like she is? Yes. Would I add a very attractive person we'd only met that evening to our sex lives? Nope. I made that part up, like the director probably did his gay scene with "my" actor's character.
Using our own lives, and minutia drawn from those around us, is how authors make their characters seem real and rounded, with lives which existed before the events in the book and which will continue after its end--unless we kill them. I work hard to give my characters backgrounds and childhoods, opinions, beliefs, hopes, fears, families, friends, weaknesses, doubts, jobs, frustrations, tempers, senses of humor, hobbies and interests, and everything else real people have which make the simplest lives rich.
I make it all up, peppered with a few tidbits from real lives if they fit in the fictional mosaic of my characters' lives.