I've written birthday posts on a friend’s page, but they don't show up. Where did they go? And how do I find them and bring them up?
If you post to a friend's timeline the day of his birthday, your post will appear in a special box on the timeline.
91 friends posted on your timeline for your birthday.
If you can't find it, you can use the "View friendship" feature to find all the relations between you and him: