The trip itself wasn't actually too bad, it was just loooooooong. Last time we flew out of O'Hare it tooks us 3.5 hours to get up there. This being winter and the holidays, we decided to give ourselves 4 hours to get there, and then three hours to deal with security and have time for dinner at the airport.
We did a one-way car rental, in the kind of large, boring American car that populates rental fleets but, alas for their industry, does not populate the imaginations of the car-buying public. It was fine for our needs, though. The drive only took 2.5 hours, and by the time we disembarked from the Hertz shuttle it was about 3:30, for our departure time of 8pm. Except the flight was already running late, bumped back to 9pm. Murphy's law of aviation, your flight always runs late when you arrive way early.
O'Hare has a bad reputation as an airport, some of it deserved. The international terminal is a joke - for one thing, there are no restaurants in it; rather, a sad little food court lies tantalizingly on the other side of a clear wall (and a long security line) from the concourse. Fortunately, the O'Hare employees we dealt with were uniformly* polite and friendly, and one had warned us about this, so we ate before making the crossing into the enforced fasting area.
(*except, of course, those at security, the best of whom were taciturn and the rest of whom were yelling)

Aidan waits in the departure lounge at O'Hare; this expression was the result of my asking him to, and I quote, "smile!"
Anyway, the flights themselves were generally fine. Aidan was a wonderful traveler. Man, I can't believe how patient he is on these long flights, he handles them much better than do I. He was disappointed by the seatback video cartoon offerings, which was a shame because he'd been looking forward to a video binge. However, I salvaged the day with some cartoons I had judiciously stored on the iPhone. Daddy rules!
At this point, we pause this travelogue for a tip for those of you who might be looking to travel internationally with a child - request a special in-flight meal in advance for your kid. Why? Because they bring those out first! Because of Aidan's dairy allergy we had requested the vegan meal for him, and so his appetite was sated long before our more pedestrian choices arrived.
After a fitful night of so-called "rest" we had a layover at Heathrow, where I was eager to check out their new international terminal. Said terminal was designed by an architect with a sadistic streak. This architect was told, "Think of the passenger experience as an adventure game, where information is to be withheld until the clever contestant can skillfully seek it out!" You exit the plane and then sort of wander, hoping the herd knows where it's going.
I do not like Terminal 5, I do not like it one little bit. Here's the thing - we were arriving in terminal 5, and departing from same. At no point were we going to touch UK soil. Piece of cake, right? You step off the plane, find your new gate, and then drink some ale and eat some fish 'n' chips while you wait for the next flight, right?
Wrong.
We get off the plane, walk down some stairs, or up some stairs, and then down or up again, then ride an elevator somewhere, then get on a train, then off the train. We ride down an elevator, to be faced with four airport employees telling everyone to make sure we discard any liquids before we get to security.
Um, wha....?
Understand the absurdity: we went through security at O'Hare in order to board a British Airways flight to London. We picked up a few bottles of water on the plane. Now we deplane from our BA flight into a terminal exclusively for BA flights in order to board another BA flight from the same terminal. Somewhere in that sequence we became security risks. And now four people must be paid to stand around telling us to throw away the water we acquired on our BA flight (this before we even get to security), because somewhere along the stairs and elevators said water has now metastasized into something too risky to take on the next BA flight. And then after we do that, we must go through a security screening, just in case somewhere after getting off our last BA flight we picked up a bomb to take on the next one.
You'll excuse me if I don't actually feel secure. Anyway, I digress...
We finally arrived in Berlin, where we waited patiently for our bags to appear. Said patience was not rewarded, as one of the bags failed to appear. My first inclination was to blame terminal 5 at Heathrow, which had a notoriously bad opening this year and temporarily misplaced some 25,000 bags. But when we received the new bag next day, it turned out that it had never left Chicago. Which leads us to another travel tip - never arrive early for your flight! It sends the message that you are in no hurry, and if you can wait, so can your bag!
But we had gotten there, and so we emerged into the 4pm darkness, ready for our first week, and Christmas in Berlin! (And I promise, it'll have more cute pictures of Aidan, and less ranting from me.)