He presented himself alive to them after his suffering by many proofs, appearing to them during forty days and speaking about the kingdom of God. (Acts 1:3 ESV)
Having been part of university life for nearly half of my life there are certain aspects of collegiate culture that are almost second nature to me. Cramming is something that I hear about all the time, it's not usually called that anymore, it's usually referred to as an "all-nighter" these days, but they mean the same. Both are when someone stays up all night before a big test to spend time studying.
Jesus allowed his disciples one final cram session. It was a 40 day all-nighter. One last shot for them to learn and latch on to the principles and passion that would be needed to steer the burgeoning Christian movement.
The resurrection changed things for them. It invited revelation and understanding surrounding the three previous years the eleven had spent in community with Jesus. It have context for all that Jesus had talked about. And it pushed them out the door toward their final lifelong test.
Jesus had one more season to train, teach, and mentor. He took a little over a month to do it. They learned from the master himself. The test was coming!