You don't get to find out exactly how curious your betta is until you take him out of those tiny cups and place him in a larger tank. They go berserk! We put one of our males in a 5gal next to the sofa and he swims up to the side closest to the sofa to watch us. Makes me think we're in the tank since all he does is swim or lounge on that side of the tank and anytime there's a movement, he's there to check it out.
Great to hear he's doing well! Are you going to put any friends in there for him?