@saab,
"Alter Schwede!" (Old Swede!).
The first meaning of Alter Schwede as an "old friend" or "old chap" ( symbolizes that very well. When Americans say "Hey Buddy!" to a friend, Germans might for instance say "Na, alter Schwede!".
Somehow, Swedes have apparently earned their reputation as good friends. Before we get to that, let me quickly explain the second meaning of Alter Schwede. In case something unexpected happens or the magnitude/scope of something surprises you, you might shout "Alter Schwede!" as an equivalent to "Wow!" or "What the heck!?!". German synonyms would be "mein lieber Schwan!" or "krass".
So now let's get to the reason for this seemingly deep friendship. The expression Alter Schwede first occurred in the 17th century and is related to the Thirty Years' War. After the end of the war, Friedrich Wilhelm von Brandenburg (elector of the Holy Roman Empire) recruited war-proven Swedish soldiers as instructors for his army. They mostly held the rank of sergeants as they were very experienced in tough military exercise (drilling). Because of that, they were soon referred to as "the old Swedes", which explains the described first meaning of Alter Schwede as a buddy/friend.
And regarding the second meaning ("Wow!"), just think of a tourist who is visiting New York City for the first time in his life and is overwhelmed by all the skrycrapers in Manhattan. There is a pretty high likelihood his first words will be Alter Schwede! (Source: Germany.info)
