Of course we have. It is difficult to reason with toddlers. Intuitively I would say you are correct. "you just got a new toy, let's enjoy that fully before we move onto the next thing" but you can't win them all. Pick your battles my friend. Let him get the toy but make sure he says thank you to his mommy for letting him get it and his grandpa for giving him the money to buy it. Build the character and habits first then you can work on logic and reasoning.