Preparing for a B-1/B-2 visa interview?

For those who have already gone through a B-1/B-2 interview, what part of the process surprised you the most?

One thing applicants sometimes overlook is how important it is to understand their own application before the interview. Being able to clearly explain your travel plans and circumstances can be just as important as gathering documents.

At Argo, we often see applicants focus heavily on paperwork while spending less time thinking about how they'll explain their situation.

Curious to hear what preparation strategies others found most helpful.