In the N.F.L. these days, young quarterbacks are all the rage. There once was a time when a team would have to wait two or three years for a young quarterback to develop, but not anymore. The Eagles, with 23-year old Carson Wentz at quarterback, are 3-0. The Broncos, behind 23-year old Trevor Siemian, are also 3-0. And the Cowboys, riding red-hot 23-year old Dak Prescott, are 2-1.

Here’s what we learned in Week 3:

■ Carolina’s opening-day loss was no blip. The Panthers lost once again on Sunday, this time to the Vikings, thanks largely to Cam Newton’s three interceptions. Carolina didn’t lose its second game last season until the Super Bowl.

■ Defense is exciting. Big defensive efforts like the ones by the Eagles, Broncos, Chiefs, and Bills can be just as thrilling as touchdown-filled shootouts. The Lions, having let Aaron Rodgers destroy them with four first-half touchdown passes, may want to look into this “defense” thing.

■ After watching the Browns’ Terrelle Pryor play quarterback, wide receiver, and safety in the same game, it becomes clear: For Cleveland to start winning they simply need to clone the former Ohio State star 52 times. Finding a kicker who can hit a game-winning 46-yard field goal would help as well.