What to preach

This coming Sunday is the forty-sixth World Day of Prayer for Vocations and I cannot decide what to preach for the occassion. So far as I can tell, I have three options:

1. Go the usual way and preach simply from the assigned readings for the day;
2. Preach from Pope Benedict XVI's Message for the day; or
3. Share my own vocation story.

I don't know that I have a preference for any one option, so I'd like your input. What should I do? Simply leave a comment and, if you wouldn't mind, your rationale.

Two years ago I shared the story of my vocation on the occassion of the forty-fourth World Day of Prayer for Vocations. How often is too often? Is it too soon to share it again? Have I waited too long? Incidentally, I preached it two years ago at the same Masses (time wise) I will celebrate this weekend, so the same people might hear it again, or maybe not.

Please, what do you think?