Breeders will usually help this process by doing 2-3 small grooms on a puppy before sending them to their new home precisely to help the pup get accustomed to the sounds and feel of grooming.
It's been very difficult to keep this up however since the pandemic has affected so much. This means you're essentially having to start over on desensitizing him to the whole grooming process.
It's certainly normal if he's needing to be reacquainted or first time acquainted, and isn't necessarily age related. You'll do him and any future professional groomers, or yourself if you choose to do the grooming, a great service if you can ease him back into this process.
Obviously the bath and dry is done as a piece but the clipping can be done sections at a time, over several days.
You can do the face, feet and sani right after the bath and dry. Then the next day, trim just the body. The day after that, trim the legs and the last day shape his topknot. If you have to break it down even further, that's ok too. He won't be the first poodle to be groomed in bits

.