Pernicious

When I was a little girl, my grandmother taught me
to listen to oncoming traffic and to stay away from things
that could cut my heart in half. Growing up, I knew that I was
destined to be with a guy who would teach me to run on the
rails, who would make me fall as fast as a cannonball and
put all my fears to rest.

*As requested by @theoneandonlycheryl for #bemymuse no. 29