I don't get jet lag. I just don't. I never have, and after flying through two sunrises, three meals, two glasses of wine, and three airports on three islands over 30 hours from Osaka to JFK with no ill effects, I'm pretty sure I never will.
I've been warned about jet lag since the first time I flew to Florence when I was, let's say, twelve-ish, and I don't recall having it back then, though I don't recall any of my friends' names back then either, so this isn't my strongest data point. Regardless, in the twenty years of travel I can vaguely recall, I have nothing vaguely resembling a recollection of whatever jet lag is.
There is enough talk about it that I have to believe that it's a thing that happens to other people, like veganism or annual dental appointments. There seems to be some medical explanation, but I'm not a doctor, so I'm going to make uninformed assumptions about what's actually going on, with more judgmental arrogance than you would expect from a brain surgeon.
Hypothesis 1: Everybody else is screwing themselves
In no topic do I hear more confidently given prescriptions with a smaller sample set and more negligible expertise than the topic of jet lag. People otherwise hesitant to take a multi-vitamin will recommend NyQuil and cocaine, along with sleep regimens ranging from physically unlikely to mathematically impossible. People who will caution you against drinking too much after your mother's funeral will hear about your upcoming twelve-hour flight and recommend you get hammered at the terminal bar before boarding.
Since the basic problem is "your body's natural responses are slightly out of whack," the response "pulp your body's sensory system into mush" seems illogical to me. A hodgepodge of techniques to force alertness or unconsciousness is just going to create a more unusual state from which the body has to recover.
Hypothesis 2: I do everything right
No getting drunk. No coffee or alcohol on the plane. Eat when hungry, regardless of time. Leave the window open, so at least your body has a clue about what's happening outside. I don't really sleep, but when my head lolls over in the middle of reading, I don't jerk myself awake, so I spend about half the flight in semi-conscious meditation through laziness.
When I disembark, I pick up the day from whenever it is and stay up until eleven or midnight, and by next morning I'm on local time. In fact, I'm in a lockstep eight-to-eleven schedule for the next week. I'm always a little tired on the day of the flight, but no more than I am during a morning work meeting after four hours of sleep.
So I recommend trying this, because it's what I've always done and I've never been jet-lagged, but I don't speculate on the mechanism because it's possible
Hypothesis 3: I'm too much of mess for jet lag to have any meaning
Culture shock is also something I seem not to get, but since the symptoms of culture shock are anxiety, depression, and irritability, it would be impossible to tell.
The same thing may be true of jet lag: my regular "routine" is staying up all hours until I fall asleep wherever I'm sitting or standing, or until I've drunk myself into unconsciousness. Since on an average Wednesday I wake up between 8am and 1pm and fall asleep between 11pm and 4am, it's possible the aforementioned eight-to-eleven lockstep is my version of jet lag. Otherwise, who would know?
Still, I prefer the last possibility:
Hypothesis 4: I am the next phase of human evolution
Not unlike a demigod, or mutant superman. Fortunately for you, a simple oath of allegiance written on the back of a twenty-dollar bill and mailed to my PO box can secure your citizenship in my world empire, long may I reign.