This was originally a system by which mounted warriors were to act, but while service to their people is touched upon the general goal of medieval knights was not saving many a damsel in distress, devotion to God, or enforcing justice; most knights defined chivalry as warfare and obtaining fame and fortune in the name of their king(s) and without any display of cowardice in battle. In a sense, it's hardly different from joining the military for the benefits that it offers, including the money that pours in from the business of war. Chivalry was basically a boy's culture: fighting other men, riding horses, power and profit and the ability to exploit that power.
The modern notion of chivalry as courtesy to women has tenuous links to chivalry as it was originally conceived. Perhaps courtly love (coined in 1883 to describe the worship of a married noblewoman by a lowly troubadour or knight and his vow to do great deeds in her honor) influenced this notion, but courtly love is, for all intents and purposes, adultery (very dangerous to both participants) and to what extent that courtly love was ever practiced remains unknown.
Dad: Because, when somebody has a certain chemical called estrogen in their body, they automatically deserve more respect than you. It's called chauvinism, I mean chivalry.
haha, yes !
-later that evening while she is chillin with her girls-
"this guy asked me to dinner, i am just gonna say i am busy."