What does my dream mean?

I had this dream last night and I cant work out what it means, some of it may seem random but i'm going to say all of it incase there is some hidden meaning behind it. Ok, it starts on a beach in cornwall, england, where I had a biology feild trip and where I met my girlfriend (it's complicated with her, she's on holiday for a month atm, you may remember from my previous quesion, and I cant stop thinking about her, she is in central america (may be important)) Instead of doing bio field trip stuff we are asked to reenact a napolionic style battle on the beach. I am on the side of the British and my gf is the commander of the enemy French. (I can kind of see what this means but I want to see if anyone has the same ideas as me). Anyways, the battle is skipped in the dream and I am walking back up the beach when a rock falls from a cliff and knocks me out. When I wake up (still in the dream + this is where it gets even more random) it is 100 years later. A guy dressed like a steriotypical west country farmer is standing over me. I look around and see that I am surrounded by a mexican/western style desert with mesa's, cacti, tumble weeds etc. I ask the farmer where I am + what happened and he says that i'm still in cornwall only it's been desert for 100 years cos of global warming. None of the people I was with in the earlier part of the dream are there, just me and the farmer. I know this dream sounds really wierd but I don't know what to think of it :s