This falls under the idea that it is an honor to be a sacrifice for the gods.
On film that may be worth looking at is Pasolini's 1969 film Medea. The film opens with Medea's royal family sacrificing her brother so the crops will grow. As I recall, the brother is smiling.
A good contrast is the 1973 film The Wickerman, which is partly an adaptation of Euripides' The Bacchae. Warning: Spoilers!
In the Wickerman, the sacrificial victim must be willing, so the entire plot revolves around tricking the protagonist into ritually accepting the role.
(Traditionally, criminals and prisoners were the victims burned alive in wickermen, decidedly not willing;)
Euripides wrote several plays about human sacrifice. Iphigenia at Aulis may shed some light:
Achilles: ...how I grieve to think I shall not save your life by doing battle with the Danaids. Reflect, I say; a dreadful ill is death.
This I say, without regard to anyone. Enough that the daughter of Tyndareus is causing wars and bloodshed by her beauty; then be not slain yourself, stranger, nor seek to slay another on my account; but let me, if I can, save Hellas.
SOURCE: Iphigenia at Aulis, 1414
Iphigenia: (to her mother) I cannot let you shed a tear. (to the Chorus) May it be yours, maidens, to hymn in joyous strains Artemis, the child of Zeus, for my hard lot; and let the order for a solemn hush go forth to the Danaids. Begin the sacrifice with the baskets, let the fire blaze for the purifying meal of sprinkling, and my father pace from left to right about the altar; for I come to bestow on Hellas safety crowned with victory.
SOURCE: ibid. 1468
Iphigenia:: Lead me away, the destroyer of Ilium's town and the Phrygians; give me wreaths to cast about me; bring them here; here are my tresses to crown; bring lustral water too.  Dance to Artemis, queen Artemis the blest, around her shrine and altar; for by the blood of my sacrifice I will blot out the oracle,  if it must be. O mother, lady revered! I will, not give you my tears;  for at the holy rites it is not fitting. Sing with me, maidens, sing the praises of Artemis, whose temple faces Chalcis,  where angry spearmen madly chafe, here in the narrow havens of Aulis, because of me. O Pelasgia, land of my birth, and Mycenae, my home!
SOURCE: ibid. 1475
Of course, Euripides being Euripides, can't resist taking a jab at the gods:
Chorus Leader: You play a noble part, maiden; but the whims of Fate and the goddess are diseased.
SOURCE: ibid. 1402
So the idea at least is mythologically documented in this play, specifically the nobility of sacrificing oneself for society. This has other roots in the Trojan War Cycle, for instance, Achilles' choice (long life or glory? If he chose life, the Danaans would not have prevailed.) You later see this idea in Sophocles' Antigone and the death of Socrates.
In terms of validation of this idea in the Aztec tradition in particular, I'd suggest looking to the accounts of the early conquistadors. Cortez and Bernal Díaz del Castillo seem to have written about this subject. [See: Human sacrifice in Aztec culture. PS--If anyone is aware of this source material online, please link!]
- If you're thanking the person who is cutting out your heart, it would almost certainly be because it is an honor to be a sacrificial victim