Are there things you just 'don't get' in life? (as in understand the rules of)

Thanks to Number in another thread (root beer) I've been thinking of the many things I've just 'not got' and done wrong.

Usually the clue that I'm not 'getting it' is the look of wonder on the faces of other people.

I'm suspecting now this may be autism related.

There are countless examples during my life but here a few.

McDonalds: I don't really understand McDonalds and I don't spend time in them without another person.

My mum used to like them so I'd take her there for lunch sometimes.

One of the 1st times she asked me to collect a menu for her and some cutlery.

I couldn't understand why these weren't on the table.

So, I went to the counter and asked for these things.

After this initial trauma, I then had the trauma of trying to understand what you are supposed to eat off of and with.

Doh.

McDonalds is a particular thing with me I think.

I was with my autistic friend on our way back from visiting his mother and we went to a McD.

He asked me to get him a 'root beer'.

So, I asked for such at the counter only to be asked what that is.

I said 'I don't know' so no root beer was presented to my friend.

Doh.

Another prime example is going to a spa and swimming baths in a hotel.

I'm not a swimmer or a spa goer.

So, the 1st thing I did was put my make-up on before going there.

Then, I couldn't understand how the lockers worked and had to get assistance.

Then, I eventually found the toilets but couldn't find my way back to the swimming pool so I walked through reception soaking wet in my swimming costume.

I was also in a church once when a service began and loads of people sat around me.

I had gone in there because I was in a strange city and cold and was using the church as a refuge.

I thought I could just sit there whilst the service took place.

I hadn't anticipated communion and although I'm not a Catholic or a church goer, and although I didn't understand what I was doing, I felt obliged to follow everyone up and take communion. 

There are so many examples I won't continue.

Is it just me or are there other people here who just don't 'get it?'.