When you write the story to have even more impact, you can write it in the I form. 

If you want the story to feel even more personal, you could write it as if the user was telling it. So instead of starting with: "Meet John,..." you could start with "Hi there, I'm John..."

What's important is to stay coherent throughout the whole story. If you started in the "I" form, keep it like this for the entire story. If you started in the more descriptive form, then keep it like that.