Davekfl it was probably just your turn, random check. Don't take it personal, I've crossed mutiple times a year the last few years at different crossings and there all different, some good some not so good going either way, their just doing their jobs. The heavier crossing are the most prone to get a full search in my opinion. All you can do is have all the proper paperwork be polite and answer all the question and hope for the best. Good luck in your future travels.
Cheers