Taking a cue from yesterday's post, I want to comment just a bit more on the idea that the Mass is always going on in Heaven. There is a lot of theology behind this idea, but the facts are there in Scripture for us to contemplate. Jesus, the Lamb of God, Who was dead and is now alive, is there presented to God the Father constantly. The Angels and Saints are constantly worshiping and praising God. The Word of God is constantly being spoken, and our salvation is being applied to us.
This is the point of the book of Hebrews in chapter 12 (go read the whole section sometime soon). Thus, for our participation in the Mass, we can see that is more than "getting something" (though that is crucial for our salvation). The Mass is training us how to live in Heaven. If we are going to become an eternal part of God's people then we need to learn here and now how to glorify God rightly. If we cannot do it correctly now, we are not allowed to enter Heaven to do it for eternity. This is one of the most significant reasons for the Mass.
Therefore, do not just "come to Mass". Learn it. Practice it. Know it. This is one of the most beautiful aspects of when children "play Mass" at home. They are showing all of us that they get it better than we do: we all need to learn how to do Mass and practice makes perfect. The choir in Heaven is perfect, let us learn to sing better. The High Priest (Christ) in Heaven is perfect, let us learn to offer ourselves better. Everything done there is according to the will of God. Let us do our best to make sure that His will is done "on Earth as it is in Heaven"; especially in the Mass.