If somehow you still haven't seen Avengers: Endgame, be warned this article does contain some spoilers.
Marvel Studios boss Kevin Feige says Stan Lee "unfortunately did not get to see" Avengers: Endgame before he died.
Stan co-created lots of the comic characters we know and love and has a cameo in every film in the Marvel Cinematic Universe (MCU).
Kevin says Stan liked waiting until the premiere of a film to see the final movie so never saw it finished.
But he says Stan did know the details of the plot from when he filmed his cameo.
Kevin Feige, who's been the president of Marvel Studios since 2007 and has overseen all 22 films in the MCU, was answering fans' questions on Reddit.
Unsurprisingly, there was a lot they wanted to ask.
Elf deserves some credit
Avengers: Endgame brought a close to what's referred to as Phase Three of the MCU - the series of films which started with Iron Man in 2008.
Or did it?
One fan wanted to know why the first Iron Man was directed by Jon Favreau, who up until then didn't have any big credits next to his name - except one.
"Jon Favreau is one of the best storytellers on the planet," Kevin replied. "And Elf is a stone cold classic."
So Elf is what got Jon Favreau the gig that led to the biggest movie franchise in the world.
Just another reason to love Buddy.
Robert Downey Jr was a hard sell
There are plenty of moments over the past 11 years that might have been difficult for Kevin Feige to sell to executives at Marvel or Disney.
He describes his time at Marvel Studios as an "amazing collaboration" but the things he says he's had to fight hardest for are, in retrospect, a little surprising.
The first was casting Robert Downey Jr as Iron Man.
Now we imagine Robert Downey Jr as Mr Marvel - the person who started it all and whose character has developed probably more than anybody else in the MCU. Kevin says Tony Stark's story arc is his favourite.
But taking into consideration RDJ's controversial past - he served a three-year prison sentence for drug possession - you can understand why some people might not have considered him a great choice to kick-start a family-friendly movie franchise.
Kevin said he also had to convince bosses of his choice to set Captain America: The First Avenger during World War Two.
'He was always worthy'
One of the biggest moments in Avengers: Endgame is the moment Captain America picks up Mjolnir - Thor's hammer.
It's one of the most powerful weapons in existence and plenty of people have tried to lift it, but it can only be held by someone who is "worthy".
So someone asked: has Cap been worthy for a while - since Age of Ultron - or did something change in that moment?
"We think he was always worthy," Kevin said, "and he was being polite in Age of Ultron".
All of that refers to a funny scene in the second Avengers movie where the different superheroes all try to lift the hammer.
The Ten Rings
Something that caused a lot of excitement on the Marvel Studios subreddit was Kevin Feige's revelation that there were plans to incorporate the Ten Rings and/or the "real" Mandarin into future films.
The Ten Rings are the organisation that kidnapped Tony Stark in the first Iron Man film, and the Mandarin is their leader.
There have been rumours that Mandarin could feature as the villain in the upcoming Shang-Chi film, and for some Marvel fans, this was Kevin Feige confirming that.
Is there more Hulk to come?
The Hulk appears as we've never seen him before in Endgame - Bruce Banner has finally managed to control him, resulting in a killer combination of Bruce's intelligence and the Hulk's strength.
Kevin says that version of the Hulk was referred to by the team as Smart Hulk. Some fans call this version Professor Hulk.
And for fans of our green friend there is great news - we might be seeing more of him.
Someone asked about a meeting Kevin said he had with Hulk actor Mark Ruffalo, where Mark talked him through his vision for how he saw the Hulk evolving.
"He pitched a lot of cool ideas," Kevin said.
"Some of which led to what you saw in Thor: Ragnarok, Infinity War and Endgame, and some of which would still be cool to see someday."
'Totally and completely'
Kevin says the shows on Disney's upcoming streaming service Disney+ will weave into the films "totally and completely".
And he says it will present an opportunity to "flesh out" some of the lesser-known characters from the Marvel Universe "on a grand scale", as well as ones we "know and love".
"It's tremendously exciting," he said.