Case: Jimmy was 21 in 2000 when the DREAM Act was introduced. Having read that in order to fully take advantage of the bill he would need to complete x years in college, he decided to go back to school. The age cap on the DREAM Act at this time is say, 35.

2013 rolls around. Jimmy is now 34. Unfort, it seems the age cap on the DREAM Act has been reduced to 30. He is no longer eligible. However, since Jimmy completed or surpassed the college requirement retroactively (prior to bill passing while still meeting all other requirements), he is still eligible for the DREAM Act.

hope that helps.