If you consider him a 40+ goal player, you have to consider him injury prone too. He 0 40 goal seasons, 1 season where he missed almost half the games due to injury. Obviously, neither one is true (yet). He could end up being injury prone (being a smaller player), he could be a perennial 40 goal guy (with scoring going up and Montreal likely adding more high draft picks). There are lots of examples of guys that start off a season hot then cool down as the physicality and travel wear them down, and that's probably more true of bad teams.
Young guys go in full of energy and are trying to make an impression while the vets know the grind of an 82 game season plus playoffs and are pacing themselves a bit better. For the Ducks, it happened to Terry a year ago... he was top 5 in scoring what, a third of the way into the season? Had a great year, but wasn't near the top at the end. He had points in what, like 15 straight games after the opener? If you go by that pace, Terry is a 100+ point player... but he cooled off and didn't hit near that, same could be true of Caufield.