I loved the episode, but this was the only thing that bothered me in it.
You have Luke telling, lets face it, a toddler, they have to make a choice that defines their life right NOW and the little guy can't even speak. It's like asking a 2 year old to pick their career path and telling them they can never go back. Luke could have just given him the armor and said 'he wanted you to have this when you were ready' which is less of a lie than Ben told him when he gave him his father's lightsaber....
Something else that struck me was Luke saying he didn't feel he was teaching Grogu as much as he was remembering. What would he actually remember? If he's 50, his time in the temple ended 30 years ago. If he's a toddler at 50, what the hell was he at 20? an infant? So where would this memory come from?