It's OK to grieve. It may even be healthy. I think it's important to be honest what we are grieving, though.
When I was honest with myself, I was grieving the image of perfecting celebratory moments with a pretty drink. I was grieving that initial feeling of euphoria that occurs for me at drink two, and now turns into crap in less than an hour. I was also grieving the "excitement" that came with knowing a carefree night could end up any kind of way: fight with spouse, close call, lost wallet, sick call to work, or weird bruises.
The real grieving should be about the decade that slipped by me in a flash, leaving me (seemingly suddenly) in middle age to pick up the pieces. Compared to this, getting upset about not having alcohol in my beverage (I still have beverages!) seems a little ridiculous.
When I occasionally feel like grieving I observe a normal drinker having a good time and remind myself that even if they live to be 110, my drink-count still wins! Yay!