A childhood belief about monsters

I think it must have started when I would wake up after having a bad dream, and my heart would be beating so hard that I could hear it pounding in my ears. I remember laying in bed in terror because I thought my heartbeat was a giants footsteps, running down the street outside, coming to my house. I was too afraid to look out the window, and of course that just made my heart beat louder and stronger, the giant was getting closer!!! I believed in giants for awhile there, and it happened more than once.