It's okay to bring child-like excitement to your birthday party planning, especially if you're not ready to venture into that mental territory that has so many adults playing down the yearly event.
Instead of merely making a dinner reservation and leaving it at that, why not bring back the fun of themes, decor and party favors in an adult form that your friends will relish?
You could give out themed playing cards with personalized labels as both a birthday party favor and a clever segue into a game of birthday poker. You may also want to remind partygoers that all bets are off if they don't ante up the gift pile.
Of course, the one thing you presumptively never got to do as a minor is indulge in the bubbly on your special day. Wine bottle stoppers make handy, stylish gifts that will have your guests pulling out all the stops at every future event. Pair them with mini cocktail shakers or a starfish bottle opener to give their wine escapades an extra whimsical twist. If you're really into cross-cultural references, hand out Japanese sake cups and watch as your friends go crazy.