Why does my puppy act like I don’t exist outside?

For context, I have a 4-month-old Golden Retriever, and I’ve had him for about 5 weeks now. At home, he listens pretty well, he responds to his name, basic commands, and seems focused during training. But the second we go outside, it’s like I completely disappear 😅 He gets distracted by everything, people, dogs, sounds, even the wind , and won’t respond unless I’m basically right next to him with a treat. I get that it’s a more stimulating environment, but I’m not sure if this is just normal puppy behavior or if I should be training differently outside. Did your puppies go through this phase too? And what actually helped them start focusing outside