My friend was dictating a letter to me. When came to the closing of the letter, he said" as I say adieu to both of you", I was quite in a lost, " what is 'adieu' ". He smiled, "well, it is the same as farewell or good-bye."

That reminds me of the time when I was a freshperson in university, when the whole class was not able to answer what was the meaning of ' so long', my English teacher, a very proud lady, sneered at us, "even my 6-year old son knows 'so long' is good-bye."

Gee, that always makes life interesting.