Why Do Japanese People Apologize?

It is thought that there are quite a number of foreigners visiting Japan who are surprised by Japanese people suddenly apologizing to them with a "sumimasen".
Why in the world do Japanese people always apologize?

Actually, the phrase "sumimasen" contains many different meanings! The most widely known meaning is "sorry" that is used when someone makes a mistake, and "excuse me" that is used when you want to pass someone on the street. However, it is surprisingly often used with the meaning of "thank you" as well!

Though it is another form of "thank you", in what situations is "sumimasen" used instead of "arigato"?

Take situations like these, for instance...

Japanese people certainly do have a over-sensitive way of thinking, so it can be hard to wrap your head around unless you live in Japan for a long while.

If you're ever in a situation where someone has apologized to you even though you have no recollection of them doing anything wrong, just think of their "sumimasen" as a "thank you".