Nobody picks a loser for a best man, so if you're the lucky guy chosen for this part, you must have a lot going for you. And you're going to need all of it to get through the next days or weeks to the wedding. You're in for a rollercoaster ride that will have your buddy questioning the point of a wedding, the point of marriage, and the meaning of his existence. That's why they invented bachelor parties. Now you know what to do, so go and do it. Clearly you're the best man for the job.