Why would the connotative meaning of a word be different from person to person?

a. everyone brings different experiences to the meaning of words.
b. dictionaries list different meanings for words.
c. different versions of the word have different meanings.
d. people do not always know what a word means.

Afirefighter is a rescuer extensively trained in firefighting, primarily to extinguish hazardous fires that threaten life, property and the environment as well as to rescue people and animals from dangerous situations.  just cut some parts to make them shorter and add some of your facts or what describes them most. or what they are supposed to do.