OK. So you’ve got Jesus, and he decides to start his ministry now that he’s the technical age of adulthood. So he uses his initiative to stay behind and teach the teachers, and ask them questions to get them thinking, and everyone’s all oooooo…
And then his mom (and dad) come and find him and say, “We’ve been worried and looking for you for three days.”
And he says, “Don’t you know I have to do my Father’s work?”
And then he shelves those plans, goes home with them, and sits in obscurity and obedience for seventeen more years…
So, question #1. Mary is with Jesus his whole life, from the Nativity to the Burial. Do you really think Jesus could be hidden from her, unless he specifically wanted to be hidden for her? It’s not “Home Alone” (“AUUUGHH! We left the Messiah behind!”), but it was a very deliberate move on Jesus’ part.
Question #2, do you think Jesus just carelessly wandered off for no reason, or do you think he had things he needed to accomplish during those three days? Do you think he was being selfish and shortsighted and even being fully God isn’t enough to protect you from acting like a dumb, impulsive teenager, or do you think that everything he did had significance, and everything the Gospel writer recorded (Luke-- which is significant) had super-significance? You could make a stronger argument that this was sinful on Jesus’ part, which we knew was an impossibility, before you could make the argument that it was sinful on Mary’s part.
Question #3 is more of a point. So, of the billions of people who have ever existed, Mary was the closest to Jesus. She nurtured him for nine months; she raised him from an infant; he continued to live with her and care for her into adulthood; they remained together through his ministry, death, and resurrection. But even she lost Jesus for three days. Not through any fault of her own, but because Jesus allowed it to happen. If Mary could lose Jesus for three days— how much more are we in danger of losing Jesus?