<human>: Could you distill the essence of the text into 1-3 sentences?

I rattled my brain for the right subreddit, and this seemed to be the best fit. Also, this isn't a throwaway, I was just surprised this username hasn't been taken yet.

 

My mom is an American living in a Bavarian town for work, and has been for a few years. I recently visited her and we chilled at a pub. A few minutes after she left for the restroom, an older man (40-50s M) walked up to me and put his arm around me. He also started talking to me (I don't recall what was said). Note that I had not seen this man previously, and the most contact I'd had with him up to this point was a brief glance at him as I casually looked around the room. I'm looking at my beer, next thing I know: "whoa, whose arm is that?"

 

Fire alarms went up in my head, and I squirmed a bit and asked him to back up (as politely as one can when both startled and having a small voice). My mom came back and I told her, "dude, some creepo just came up and put his arm on me." She looked at me with mild frustration, saying "It's normal here for people to do that. This isn't the US. You shouldn't be so quick to shake people off like that."

 

Now, I'm still of the opinion that no, it's totally double-plus ungood for some random dude to come up and put himself around me like that. I just figured my thought process would be an almost-universal one in the West. I also read up a bit on German culture before visiting, and I definitely don't remember reading anything about touchy-feelies with strangers.
<bot>: Do Bavarian Germans and United Statesans really have different cultural standards when it comes to greeting strangers at bars, or is my mom full of die Scheisse?