I'm not saying that if Goff's dad said it, then it must be true. Parents of course have filters through which they see their kids.
It just reminded me of stuff his college and high school coaches said, as well as some of the media, about how he is so resilient and has always played "young". Started as a freshman in High School. 18 years old starting Big School QB. 21 years old starting NFL QB. And how he is able to overcome his teams and his own growing pains and learn from the bad times instead of going into a fox hole.
I have no idea how good of an NFL QB he'll wind up being. Too many intangibles and circumstances have to line up. But he HAS the tangibles and his history has been to play before he was physically or mentally matured, and play well, and get better year after year and in time lead his team to wins.
No reason to think that same trajectory can't happen with the Rams. We'll just have to wait and see. But I can't imagine that McVay has him on a one-year timeline. That is, he becomes a top 12 or 15 NFL QB this year or McVay loses confidence in him as the starter. But, of course there has to be noticeable improvement and steady development. If not.....then perhaps it is hello Cousins.