that's not the point. you can redefine gratitude all you want. but then your use of of the word gratitude no longer applies to the feeling i want to express when someone gives me something.

in other words: your redefinition of the word gratitude to imply narcissism does not make my expression of gratitude narcissistic.

we are talking about observable human behavior here, not about word definitions. if you believe that expressing gratitude is narcissistic then you have a problem. (and if you believe that the definition of a word changes the meaning of an act, then you have two problems)