Terrible 1’s??

My son just turned 15 months and is a terror! I know he’s just curious and figuring out the world, but he’s making me crazy. When I say “no” he looks at me, smiles and laughs, and continues the bad behavior. I remove him from the situation, give him a new distraction, and he goes right back to the old activity. When it comes to breaking things or safety I need to be able to stop the behavior without it becoming a game. I’m trained in Early Childhood Education, and I feel like I need to just throw all my knowledge out the window. I’m incredibly frustrated......