POW #2: Juxtaposition and Contrast

Military Induction Requirements
When I'm Sixty-Four / Paul McCartney

When I get older losing my hair,
many years from now ...
There are many types of hair styles that fall within acceptable military standards. Prospective recruits should note that there are minor differences between each branch of the service, and guidelines are generally far harsher for new recruits.
Will you still be sending me a valentine,
birthday greetings, bottle of wine?
The minimum drinking age on a DOD installation shall be consistent with the age established by the law of that State as the State minimum drinking age.
If I'd been out till quarter to three
would you lock the door,
Since there is no curfew stateside, there's no time when they will tell you that you "have" to be in the barracks.
Will you still need me, will you still feed me,
when I'm sixty-four?
If you stay in the armed forces for 20 or more years, you will be eligible to receive a pension based on a percentage of your basic pay; if you stay in the armed forces for 40 years, you will be eligible to receive a pension based on 100% of your basic pay.