Question:
Answer:
Yes, Jesus necessarily had to know he was God as a child; otherwise, his taking on a human nature would’ve demonstrated he wasn’t God, which, of course, is heretical. Many erroneously conclude that Jesus didn’t know he was God as a child from the closing verse of the account of his being found in the Temple by the Blessed Mother and St. Joseph: “And Jesus increased in wisdom and in stature, and in favor with God and man” (Luke 2:52).
In short, Jesus could grow in wisdom insofar as he appropriated knowledge in a new way through his human nature, as a boy and as a man, but he necessarily couldn’t have had a net increase in knowledge, given that he’s first and foremost a divine and thus omniscient person. And his divine intellect informed his human intellect of the reality of his divinity.
The hypostatic union, that Jesus is both true God and true man (CCC 464-69), is a profound sacred mystery, i.e., a truth we will never fully grasp, second only to the Holy Trinity. So we need to bow at that mystery when we reach our human limits and not venture into doctrinal error in misguided attempts to explain it.