Maintaining a sense of fun when playing high-stakes blackjack involves focusing on the enjoyment of the game rather than solely on winning or losing. It's important to approach the game with a positive mindset, viewing it as entertainment rather than a serious financial endeavor. Players can engage with friends, enjoy the atmosphere of the casino, and celebrate small wins while keeping losses in perspective. Setting personal limits and acknowledging the unpredictability of the game can also help in managing stress.