My uncle told me that he was told to change into his civvies before leaving the airport after arriving in San Francisco .
If he came back between 1969 and 1971, it was probably for his own protection.
That was my experience too when I came back through Seattle.
The U-Tube vet is correct. Coming home was a psychological shock and disorienting. Just not many hours earlier, I was (as were many others) in a long, deadly 24/7 struggle only to return overnight to a completely foreign world (peacetime America) inhabited with many fellow countrymen who didn't understand and many whose hatred was palpable toward anybody in a uniform. It was as if "we" were to blame for the war. So, we became a target for their infantile and demented rage. The left then was as vicious as now and just as stupid and uncaring. Even family couldn't really understand or relate. It wasn't their fault. They didn't even know what questions to ask so mostly tried to avoid the uncomfortable subject except for the briefest of shallow conversations. Only those who had been through it could truly relate - like the WWII or Korea vets. Thirty days on a ship with buddies would have been a real help in adjusting to a normal civilian life.
I suspect a lot of veterans returning from Iraq/Afghanistan had similar experiences except in Vietnam the country was much more fractured. Unfortunately, some vets never truly adjust to "normalcy".
War really is a hellish business and especially for those directly involved whether military or civilian. That is why those actually involved never want it on our shores or anywhere near home or family.