Last night I stayed at a rowdy hostel and had broken sleep and ended up doing the WBTB technique by accident. About 5 or 6 in the morning I dreamed I was sitting under a massive white hot-air balloon and flying over the countryside towards a castle. I have never come across this in my dreams or in real life before and I'm pretty sure it's because I stayed at the hostel (I slept in a bunk bed but it was bottom bunk) as I've read that where I sleep can affect my dream content.
Does anyone have an explanation as to why the content of our dreams changes when we sleep at different places?