I have answered this question on three occassions just this week from people who say their dog is “stupid”. Dogs are like horses in that respect. A horse won’t know what to do unless you hold tight the reigns and lead him.
Dogs can be confused by the way you train them. If you don’t remember the correct command words you originally used to train your dog, your dog will be confused and do nothing. If you don’t remember the correct hand signals, how do you expect him to follow your commands. If you say “Here Boy” when you call him instead of using his name, he’s not going to come when he’s called.
Dog’s are very smart, that’s why they’re called “man’s best friend.” They’ll do anything for you. But don’t try to trip him up by changing the original rules you taught him. If you trained him to “come” when you clap your hands twice, don’t stand at the back of the house clapping your hands repeatedly. He’ll only be confused. That’s not what he learned.
If you need to reinforce the commands, carry little treats in your pocket so you can reinforce his completion of the command. You need to reinforce those commands at least until he obeys without hesitation.
Either write down the special words for commands you use, or use a training program that will guide you well. Actually, a good training program is a great way to train on the fast track. A blue print to follow will help you to train your dog quickly and you can easily track the command signals you use so you don’t forget.
Get into a habit of using all of the commands and training your dog every day. This will help both you and your dog to remember the signals.