Well, that's what happens when you try to force Content into a Lucid Dream. You see, dreams take quite a while to fashion and configure. They are like movies. yes, they are fluid enough to respond to your inputs and choices, but only within the context of predictable dream actions. But when you significantly want to altar Dream Content by adding your own characters, then the dream will sometimes rebel. to heck with your old brunette girlfriend... and the Dream Mind will stick in the character of a Blond because her image had already been configured.

Ordinarily I always ask my Higher Dream Mind to have a Big Dream made up and in storage, so that when I do go Lucid, I can levitate and fly away for those kind of ordinary dream scenes you find yourself in. For instance, if I were to find myself in a crowded Eatery, I would get up and walk out and Levitate away, anticipating that I would soon lose Altitude and land into a prepared Dream Scene ready for an Important and Pre-Planned Dream to unwind. If there were any important Dream Characters that the Dream Self insisted I deal with, then they will be able to levitate also, but most of the time, dream characters that are merely making up dream scenary are quite ground-bound.

So I would advice anybody to walk out upon ordinary dreams and find your Big Dreams, but without forcing or attempting to manipulate Dream Content. If you consistently ask your Higher Dream Self for bigger and better dreams, then it will go to work and create bigger and better dreams. But if you insist upon directing your own dreams, impromptu, from the materials of your limited conscious mind, I can't imagine how the results could be nearly on the par with what your Dream Mind could do if left unfettered.