When I was younger (around 10-12) I had this recurring dream, where I was on a train that was going really fast in somewhere like a cold mountain range or the Antarctic, it was covered in snow absolutely everywhere. There are deceptive snapshots that I remember really well, so there was a polar bear that was on the train further down my window looking out and seeing the polar bear bear and a polar bear was angry to look like it was running towards me but I wasn't moving, the trade also fell over on the site of the tracks or crashed.
This dream may indicate that you were experiencing some kind of instability or insecurity in your life at the time, as represented by the train being in a precarious situation. The cold winter landscape and the polar bear could be symbolic of feeling alone or isolated. The anger of the polar bear may represent a fear or threat that you were facing in your waking life. The fact that the train falls over or crashes suggests that you may have been feeling a sense of chaos or loss of control. Overall, the dream may have been a reflection of your feelings of vulnerability and uncertainty during that period of your life.