I took Bende to a basic obedience class right around the 6 month mark. he went to puppy class before and daily to daycare, knew already many commands, was a pretty reliable pet at home etc... sure enough we entered the room the first time and he started jumping up and down on the leash, whining and barking (he is usually not a big barker) and all he wanted is going up to all the dogs and play with them... he was the youngest dog in the class and definitely catching everyone's attention from the get go haha. he turned around within couple of classes and we took several other classes at the same place, we even did his CGC there at 10 months.
by the time we got to the exercise walking thru a place crowded with dogs he could not care about anyone else just me. I would say that is the equivalent of the walking bird exercise for hunt training in terms of challenging a young pup in a classroom, needs careful building up so that they are set up for success.