For some reason I assumed you were European.
Most people do (which has occasionally been WTF in and of itself), and at this point in America's illustrious history I take it as a compliment. I think it comes from being a military brat whose accent and speech mannerisms were decided more by copying Monty Python voices than by the various states which I got trucked through.
I probably owe a great deal of my personality to heavy-weight exposure to the Pythons during my formative years... When stressed, I will rotate through accents and dialects without consciously realizing it, which has probably given more than a few other people WTF moments of their own.
Such things can be rather strange. I am often mistaken for being British, both in writing (which is quite understandable), but also in the flesh, as it were, when I do speak English. It is not something that I regret, however. I rather like it, on the whole. I am unsure why, but since I was also greatly exposed to British works and British television when I was young, I think that we have identified the stiffed-upper-lipped vector.
As a note on English accents in the Nordics, they come in two flavours. Either of American or British influence. I often think that this depend on what sort of English that the individual in question have consumed the most of. There is a fascinating demographical study in the subject, no doubt.
Accents are quite interesting. My Swedish, for instance, is defined by not being an accent at all. It is much like old BBC English, or American broadcasting standard speech. However, I live in a city that have a rather strong regional accent tied to it. You can hear it very clearly. For some odd reason, I never picked it up. Quite a few times, I have talked to people who have then asked me how long I have lived in the city or where I lived before I moved, and they are always surprised to hear that I am native, as it were.
As an aside on the theme, I am a rather fuzzy man, in many senses of the word. I have always been, I had uncommonly hairy arms as a child. I remember this, for I remember that people thought that I was Italian when I was in school. Rather amusing.
As for tipping, I am rather happy that a tolerable salary is already built-in where I am. It has some decided drawbacks; everything is a bit more expensive and the restaurants cannot always afford to hire as much staff as they could use, but my word, tipping seems like such a complicated business. It is still possible to tip as a half-symbolic bonus, a show of appreciation for remarkable service, but I am glad that I do not have to in order for the waiter to make a cut of the income.