the main difference of the passages which can be compared as similar is the meaning (here and now rather than the here after or vice versa).
as for the accounts of where jesus was in the missing years there are clues in the bible that he hadn't gone too far away from his home town, and certainly his father (Joseph) was still well known in the area so hadn't gone anywhere for too long, not to mention that he didn't fulfil the requirements of the old testament to be known as messiah/christ (both have the same meaning - anointed one - in different languages (Greek and Aramaic?)).
comparing the sayings removing the meaning or overall aim of the sayings is like calling a book a movie, they aren't the same thing and they shouldn't be viewed in the same light! Just because there are things which can be respected doesn't mean they are the same
He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them.
But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion …
He must be able to hear them from persons who actually believe them … he must know them in their most plausible and persuasive form.