Amateur psychoanalysis hour is over.
Achem, sits up straight.
Well... I'd propose that the motorbike represents a symbol of freedom, escape, excitement and control.
You were manifesting unconscious desires for carefree attitude of your youth. You want to leave behind some troubling thought or responsibility.
You feel like your life is in a rut and hark for the simpler times in when you found pleasure from testing your limits, and the satisfaction of acquiring new skills through physical pursuits.
You look in the mirror and see someone that will never be better than they were, and a dwindling desire for new experiences that worries you.
Your dream is the fear of becoming old.