This is how it looked before 1989:
Every male had to go to the military commission at the age of 18. They took personal info, performed basic medical exam and asked questions. All with the interviewed person standing naked in front of the "commission".
Any males who did not get into a university, or were inveligible to get to it got drafted for 2 to 3 years, depending on the formation. Physical conditions and "knowing the right persons" helped in avoiding the service.
All university students, inlcuding women, had to attend military classes. One full day each week. We used to say that guys were trained how to kill, while gals were trained how to treat those who only got wounded, i.e. girls were educatad in medical care, mostly one that would be useful on a battle field. Both grups had some propaganda subjects aimed at building morale and such.
After graduation girls were free and clear (there were some provisions for medical students thouth), while males were suppossed to go to active duty for one year. They were granted the rank of Warrant Officer 4th Class to start with, and by the end of the duty they received the ranks ranging from Second Lieutenant to Lieutenant (rare) and Captain (extremely rare).
Educational background was considered in regards to the formation to which men were assigned. Many of Western European languages students were assigned to radio operations, intelligence, internal security, border control and similar.
It should be also noted that all Poles at the secondary level were also taught military and basic medical skills. The subject was called "przysposobienie obronne" (defense preparedness?) and included some theory and some weapons practice. Most schools were equipped with a small armory.
If you haven't served before the age of 27, you're exempt from military service, right?
I think it was 29 but make absolutely sure and call the consulate. I would not depend on info posted by someone youu are not sure about. Unless of course you don't mind tinkering with guns ;)