Here's something a bit more interesting, but based on your idea :
You didn't take the horse/gear from your father, but from a wounded knight that collapsed in front of your door. You tried to heal and feed him while he was telling you about his noble cause but, in the morning, you find out he died during the night. You then decide to take his place and fulfil his destiny.
I'll let you chose what "cause" the knight had though...