I really don’t know why they bothered as there was every chance that the departure time would be something wildly different and if the experience of the last time I took this flight was anything to go by, then I would have at least two, if not three gate changes!SFO is a really easy airport for transit especially from International to T3 where United hangs out. A quick right and then a left from the customs area brings you to a man who is ready to take your bags if you are through-checked. I wasn’t so I took the relatively short stroll to the check-in area. Most check in is done by kiosk and I was able to access my reservation by swiping my credit card. A few quick questions and I was in possession of my boarding card. While this is going on staff patrol the lines ready to help but, more importantly, to tag the bags and send them on their merry way. From there it was on to security which, while busy was not too bad as they seem to use some form of crowd control. Of course, Sod’s Law comes into play at this stage as you are sent to the shortest line which immediately grinds to a standstill for some reason or other.
This time it was an elderly gentleman immediately in front of me who was having a rant about the whole security issue. I’m not sure what his problem was but I watched with interest as the TSA guys looked at him impassively and wondered if he would be carted off to some back room somewhere. When he had finished he wandered off and the TSA guys simply shrugged their shoulders and carried on. I went into the standing-up-with-arms-in-the-air machine which showed up something in my pocket. Ooops, my iPhone! It had to be screened and while I was waiting for it a couple of the guys started talking about the guy with the rant and other similar incidents. I overheard him say that a man earlier had refused to use the machine and when told he would have to have a pat-down said, “Oh, so you want to legally sexually abuse me then?” Some people!Once through I went to the gate area and contemplated my options. There is a rather nice bar/coffee shop in that area and I decided that a glass of chilled white wine would be a nice way to while away the time while waiting for the plane and catching up with all that was happening in the world courtesy of the rather good wi-fi they have in SFO.
At the bar I placed my order and the lady sitting on a stool next to where I was standing said, “You’re gonna need more than one if you’re waiting for a plane here” She was right! By this time the flight time had changed twice and the gate changed once! Back at the bar she was still there and I told her she was right. It turns out that she and her 92 year old mother had come in from Montreal at 11:40am only to find that their onward flight to Redding had been cancelled and been rebooked on one leaving at 3:47pm. I returned to my seat and after a little while waved at them as they left to go to their flight. They returned shortly afterwards spitting feathers! The table next to me was empty and they decamped there while telling me their tale of woe. It seems that their flight went out early at 3:20pm - without them!! 
Well that was the cue for more drinks all round as we bonded with various tales of woe. She was also worried as she had lobsters in ice-boxes and she hoped they would be OK. About an hour later her phone rang. It was her husband. The lobsters had arrived but where was she? LOL! 
In the meantime the Departures board announced another time change and another gate change. Eventually they decided to go to the gate area and in the fullness of time I saw them boarding - but not before I had yet another gate change!At last it was time for my flight and I happily boarded. The Embraer has a 1-2 configuration so I was happy in the knowledge that in 5A I would have no-one behind me. I was less happy when I realised that a dad with his 13 month old daughter was behind me but that state of affairs was not allowed to continue as 6A was an exit row. A game of musical chairs followed as the cabin crew (who looked suspiciously like Alan Carr but with straight teeth) sorted everyone out so that Dad and baby were across the aisle from me. At one stage, just before departure I thought I detected a small plume of smoke above Dad’s head. Eeek!, I thought to myself but when I looked closer I realised he was smoking an electronic cigarette. For those of you who read the TR where the OP admitted to smoking an electronic ciggie in the washroom, it did look very realistic.
We were soon on our way. Dad made up a bottle for baby who promptly fell asleep and remained so for the rest of the flight. The flight itself was uneventful - yes, truly! Soon we were landing in Eureka/Arcata airport where my host was there to greet me. We had a 45 minute drive to his home and some some 30 minutes after arriving there and as I was nursing a rather nice T&T my phone beeped. It was United telling me of the delays and the gate changes!!
