Messi's Argentina overcame Van Gaal's side on their way to World Cup glory in a chaotic quarter-final clash.
An ill-tempered game went to penalties after the Dutch staged a late comeback - but the match will be remembered for Messi's personal feud with the opposition.
The Argentina captain infamously cupped his ears at veteran boss Van Gaal after converting a penalty in normal time and raged at Dutch goalscorer Wout Weghorst in angry post-match scenes.
Most assumed Messi was riled by Van Gaal's pre-match comments. The Dutchman said: "It's not that difficult to come up with an answer as to how to stop him [Messi]. You might want to block and close the passing lines. I can't see this creating too much of a hoo-ha."
However, Netflix documentary 'Captains of the World' has forwarded another theory, related to Messi's hero Juan Roman Riquelme.
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French journalist Julien Laurens said: "Van Gaal nearly destroyed the career of Messi's idol Juan Roman Riquelme.
"The Dutch coach refused to play the Argentinian at Barcelona. When Riquelme scored for Barcelona, he would do his trademark celebration towards Van Gaal.
"Messi never forgot this."
Messi touched on his close relationship with ex-Argentina hero Riquelme in the same documentary. The Inter Miami star said: "For many years, I've been talking to Roman.
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"And during the World Cup, we spoke after the matches."
The 36-year-old admitted to feeling 'disrespected' by Van Gaal and the Netherlands immediately after the World Cup clash, but later said he felt some regrets over his behaviour.
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Speaking a month after the tournament, Messi said: "The truth is that I hadn't thought about it. He came out at the moment and yes, he knew what he had commented before the game, what he had commented.
"Some of my teammates told me 'you saw what he said' on purpose. We got 2-0 and then at the moment, I don't like what I did, what happened later with the 'go over there'.
"These are moments of great tension, a lot of nervousness, everything happens very quickly and you don't have time to think about anything. Actually, nothing was planned, it happened like that and as I say, I don't like to leave that image."