We don't have Dr. Pepper, but we have Root Beer

[aK13]

I used to be an avid Dr. Pepper drinker, and since have gone back to mostly Coke, but I still enjoy it from time to time. However, at restaurants, I ask for Dr. Pepper and they tell me they don't have it, but have root beer.

Am I missing something here? I can't figure this out -- the two drinks do not even taste remotely similar, and I hate root beer.

Nobody I know has a clue, either.