Alice, you'll have a great time on Celebrity. Is this your first ever cruise, or your first on Celebrity?
If you scroll down a little further on our main page, you'll see the "Roll Calls" section. Take a look in the Celebrity section to see if anyone else has posted about Dec. 19, and leave your own message there.
Whether or not anyone else on this board is going, it's likely that there will be other singles going on the cruise. In the first day or two of the cruise, there will be a gathering for "singles and those traveling alone." It's a good way to meet others traveling solo. Also, cruise lines often try to seat singles at the same table in the dining room, if you have early or late dining (probably more singles at late dining). You can approach the Maitre d' when you board the ship and ask if your table has other singles at it. If not, he may be able to move you.
There is an active discussion in the Royal Caribbean section regarding solo cruising. Check it out, if you haven't already done so. Also, you can search our previous discussions for threads regarding traveling solo.