I am saddened when I see a large number of people leaving our parish church immediately after receiving Holy Communion. I always believed we were to stay until we received the final blessing. Am I wrong?
You’re right; we should stay until the end. Those who don’t are letting their habits of haste pull them out of what should be an atmosphere of reflective gratitude. If that atmosphere is not there, you might encourage your pastor and your director of liturgical music to create it. If it is there and some are not affected by it, you might suggest the need for a few homilies focused on the centrality of the notion of gratitude to our faith and religion. The quiet time after reception of Holy Communion is, after all, intended to be a time of thanksgiving.
I can recall being encouraged as a child to recite a prayer called the “Anima Christi" after reception of Holy Communion. Perhaps you remember the words: “Soul of Christ, sanctify me. Body of Christ, save me. Blood of Christ, inebriate me. Water from the side of Christ, wash me. Passion of Christ, strengthen me. Within thy wounds hide me. Permit me not to be separated from Thee. From the wicked foe defend me. At the hour of my death call me, and bid me come to Thee, that with thy saints I may praise Thee forever and ever. Amen." If prayers like this were available in the pews, perhaps there would be fewer departures before the final blessing!