What is your most memorable cultural shock?
你印象最深且感到震惊的文化差异有哪些？

获得好评的回答@Dave Samwell:
Some friends and I go to a bar to have a few beers before dinner. Beer is expensive in Japan and so we order a couple of pitchers to save a few precious yen as opposed to bottles or individual pints.
我和几个朋友在晚饭前到酒吧喝啤酒，在日本啤酒很贵，所以我们只点了几罐啤酒，而没有选择按杯或者品脱计算，这可以省下点钱。

We finish the beers, ask for the check, get it and leave some money on the table. It came to 4990 yen. We leave a 5000 yen note, thank the waiter and leave.
我们喝完酒，准备结账，然后将钱留在桌子上。总共4990円，我们留下5000円然后离开。

As we are an entire block away, we hear someone shouting behind us, and waving a piece of paper. We quickly realise it is the waiter from the bar.
当我们已经出了店，听到后面有人在喊，拿着一张纸币。我们很快认出是那家酒吧的服务员。

He doesn't speak English, we don't speak Japanese but he had chased us out of the bar for an entire block to give us the 10 yen in change. This is worth around 0.06 (10c USD).
他不会讲英语，我们不会讲日语，但是他追了我们一个街区只为了找我们10円零钱，而这差不多相当于0.06美元。

Tipping doesn't exist in Japan, or even simply leaving a tiny bit of change to save the waiter the hassle of getting you the change isn't a thing.
日本没有给小费的习惯。如果你给了服务员小费，也只会给他们增加麻烦，他们还要将钱还给你。

From there on in, I never tipped and waited for my change everywhere I went.
从那之后，我从不给小费，会等服务员找零钱给我。
 
获得好评的回答@Richard Muller
I was in Shenzhen, China, and a family stopped me and my wife and asked us if they could have their children take a photo with us. They were visitors from the interior of the country, and had never seen an American before.
我在中国深圳的时候，有一家人拦住了我和我妻子，然后问我们是否可以和他们的孩子合张影。他们是来自内地，从没见过美国人。

A similar thing happened in Shanghai. This time I was alone walking across the Waibaidu Bridge, and a group of teenage girls asked me if I could pose with them for a photo. I was happy to oblige, and I recall them all giggling as the photo was taken.
同样的事发生在上海。我一个人走在外白渡桥，一群少女问我能否跟他们合张影。我很乐意，在拍照时我让他们都大笑。

Another surprise: I was in Pudong and I couldn't find the entrance to the subway . I approached a man who was walking near me, showed him the ticket I had for the ride, and he nodded vigorously. Then he indicated I should follow. We went about 4 blocks; he pointed to the entrance, smiled, turned and walked away. I had no time to offer him a tip, which (in retrospect) was a good thing because it might have been taken as an insult. I couldn't believe that he had taken so much trouble for a stranger.
另一个惊喜：我在浦东找不到地铁出口。我询问了一位正在走近我的男士，给他看了我的票，他猛地点头。然后他让我跟着他。我们走了四个街区，他微笑着指了入口处，然后转身离开。我来不及感谢他给他小费，不过回想起来，给小费可能是一种侮辱。我无法相信他可以为一个陌生人做这么多。

Again, similar experiences repeated themselves across China. The friendliness of the people, their courtesy, and their eagerness to help was wonderful. I don't know if that classifies as "cultural shock" but it made me think about the US, and how I rarely experience such courtesy in my own country.
我在中国有许多类似的经历。人们的友好热情、热心帮助他人让人感觉很棒。我不知道这是否归结于“文化冲击”。但这让我想到了美国，在美国我很少感受到这种友好。