He won't listen, chews everything, pulls on the leash. Don't panic: your dog hasn't turned bad, he has become a teenager.

Overnight, the docile puppy seems to have forgotten everything: recall no longer works, shoes disappear, the leash becomes a battle. This phase is normal, sometimes trying, and it goes much better when you know what to do.
5 keys to get through your dog's adolescence
Keep rules simple and consistent
Your dog tests limits: give him clear rules, the same for the whole family, every day. Consistency reassures more than strictness.
Give him something to chew
Mouthing is a need, not a flaw. Offer suitable chew items and put away what must not be touched: you guide the urge instead of fighting it.
Rebuild recall through play
Recall is built in small steps, with rewards worth coming back for. A recall that succeeds often beats one demanded too early, and a long line gives you time to get there.
Spend his energy, in his head too
Walks, sniffing, small thinking games: a mentally tired teenage dog is easier to live with than one who is merely out of breath.
Stay positive, even on hard days
Shouting and punishment wear down the relationship without fixing the cause. Reward what you want to see again, and remember it is only a phase.

Go further

The River and Its Bed, Book 1
A positive-training guide for teenage dogs: 11 chapters, 7 cheat-sheets and a 14-day programme to channel your dog with joy.
Discover the book →Your dog hasn't forgotten you: he is growing up. A little method, plenty of patience, and this stage will become a lovely story.