Yes, in the world of lucid dreaming patience is definitely a virtue. It seems as though you’re not associating the clock with dreaming. I also recommend practicing while you’re awake…think about dreaming EVERY time you see a clock whether awake or asleep. Soon enough, your brain should start linking up a clock with dreaming and you can do your RC. If there are any other symbols (dream signs) that appear a lot in your dreams, you should work on associating those as well.

Good Luck!