“No one is allowed to make eye contact with him.”

Disclaimer: As I mentioned, these answers are coming from people on the internet. People on the internet like to... let's just say "embellish" things, so take their stories with a grain of salt. 

"I saw Goldblum at the Seattle airport years ago. I was staring at him as he walked by, and we made eye contact. My face lit up, and he made a 'shhhh' gesture with such a sneaky-looking smile on his face. It was fantastic."—u/odedzbread

"I remember when he and Angelina Jolie were wearing vials of each other's blood. It was one of those things in all the magazines at the grocery store check out at the time."—u/Eon88

Note: Hugh Jackman's most recent mention of this organization that could be found was from a 2009 interview with Oprah Winfrey. It is unknown whether he is still part of the organization.

"I’ll add a couple known 'oddities' off the top of my head: Kisses his son on the mouth (including forcing his 11-year-old son to hold an extended kiss for a video); abstains from eating any plant of the nightshade variety (including tomatoes), caffeine, white sugar, and iodized salt; he wears specialized pajamas to aid in sleep recovery; and, of course, he is completely obsessive (I guess you have to be to be the GOAT)."—u/Frohirrim

"There is just something not right with that guy... I can’t put my finger on it, but he’s off."—u/Killowatt59

"Have a friend who is in charge of security at music festivals. At this one festival, all bands had a large outdoor area behind the stage to hang out in, with all the amenities and parking for their buses. He got pissed at my friend for not letting him leave that area to ride his bike around the street, because he refused to wear his credentials because he’s too famous for that. 

My friend told him the rules are the rules for everyone and wouldn’t back down. My friend ended up getting read the riot act for not letting him through. He rides his bike down the street, does a few circles, and apparently, that was enough for him. Also, no one is allowed to make eye contact with him."—u/spawn_of_santa_

"I like how we know who this is about without the name."—u/RoseyDove323

"There have been rumors for years that he [allegedly] listens to music with headphones on when he has sex. Makes me laugh every time."—u/Lopsided-Muffin9805

"The birthday thing is hilarious when you know how he does it. He starts by looking sad on set. When someone asks what’s wrong, he says that he’s sad no one remembered his birthday. Then he waits to see how long it takes for someone to throw a big surprise party with cake. He says it works every time, and it’s never his birthday. 😂"—u/IneffableOpinion

"Yup... that taxidermy collection is something for sure. Not my thing, but you go, girl."—u/alexander_wolf88

"Didn't he also stalk a random woman while preparing for his role in The Fall?"—u/ThatsAPaddlin1066

"Decidedly less whimsical."—u/snacksandmetal

Note: Some comments were edited for clarity.