Have you ever noticed that as soon as you start fussing, your puppy hangs his little head and tucks his tail between his legs in despair? He knows you’re upset and has no idea what to do about it. Now, if it’s because of his “accident” on the floor, he’s really confused. He had to potty and you weren’t there to take him out - or you were too busy on the computer to stop and notice his needs.
At some point his bladder couldn’t take it anymore and now he has your attention, but in a negative way. Scolding a puppy (or even an adult dog) that is new to your home for accidents is useless. Successful puppy house training does not include teaching your dog that you have a short temper and your love is conditional. You don’t show what you want him to do, so nothing is learned. Positive reinforcement focuses on teaching what you want the puppy to do instead of shouting about what you don’t want.