This Theory About Jack On 'This Is Us' May Explain His Drinking Problem

This week on the past flashbacks on This Is Us (the parts I like to think of a This Was Us), we got a deep dive into Jack's first fight to get sober after Rebecca delivered her ultimatum that the drinking had to stop. But it wasn't how he stopped the first time that was the big reveal, nor was it the images of his father's drinking problem. It was the question that was raised by a three second clip: Did Jack fight in Vietnam on This Is Us?

Back in Season 1, when Jack was fixing an older woman's car he revealed that, like many men of his generation, he was in the Vietnam War. But what he said about it was that he was "a mechanic." I don't know about you guys, but from my M*A*S*H watching days, I was picturing a guy like Rizzo, drinking under jeeps and basically trying to do as little as possible until the war was over and he could go home.

And now it seems like that was just a lie, because what we saw Tuesday night was no hanging out under a jeep drinking. That was frontline infantry stuff. The kind that drives a man who comes home to drink to handle to PTSD.

Last season, when Jack's drinking problem came to light — and this season, which has focused on drinking as the possible cause of the Pearson patriarch's untimely demise in 1997 — there wasn't a reason behind the "why does he drink?" He merely does, like his father before him. His father was a man who drank, because that's what men of that generation did. Jack drank because addiction is both hereditary and also learned behavior.

But here's the thing. We never considered that there might be a "why" behind Jack's alcoholism. Men who came back from the frontlines, as Bruce Springsteen once reminisced, weren't the same anymore. War, especially the ones in South Asia against a nebulous communist enemy, was brutal. Vietnam was a world where speed got you up and weed brought you back down... that is if yours wasn't an outfit that scientists tested LSD on.

So how bad was Jack's PTSD? It may have at least been bad enough that he was willing to lie to those he met later about what he did there and what he saw. But was that a case of suppression? (You know, not a lie, just a sin of omission, a thing you don't want to remember.) Or was that due to the fact that those memories tortured him deep down to the point that drinking was the only way to ease them?

Taking it a step further, if Jack has serious untreated PTSD that he's been self medicating this whole time, how does that time back to the fateful night, the one that will happen less than a year after he confesses to his Katie that he has a drinking problem?

As we know, Kate still blames herself. We've theorized many reasons for this, but what if it's because when suddenly surrounded by fire, he flashed back to the horrors of war... and freaked out? What if the reason that Jack is killed in the house fire is because he couldn't bring himself to move or get out because in his mind he heard gunfire and screams of death all around him?

We may learn more next week, as Kevin goes on set for a Vietnam war movie (starring Sylvester Stallone, natch) and reenacts the very life his father drank so hard to forget he lived.