That is how I felt today, everybody including myself was just plain incompetent. So here is the story. I decided today would be a good day to replace the wheel bearings in my boat trailer. I pulled off one of the hubs and took the bearings down to Bennett Auto Parts. The salesman looked at them and came back with a hand full of bearings and started comparing them. When he came up with what he thought was a match I asked him if he was sure. He said yes. I knew better, and thankfully he only had one set and I needed two. So I headed to Auto Zone. The parts man there took my bearings back to the stock area and in about 10 minutes came back with 2 sets of bearings. I didn't check the numbers I trusted that he did. Got home and guess what the races didn't fit tight in the hubs. So back to Auto Zone to return them. I headed to Northern Tools where they have 1/4 of the store dedicated to trailer parts. I had 3 salesmen help me find the right bearings. Once again these guys just compared the old ones to the new ones without looking at the numbers. I knew better but didn't say anything, I took the new bearings out to my truck and the inner bearing race once again didn't fit the hub. The outer bearing did so I went back in and got the right inner bearing. I got home and put the first hub back together and damn it the outer bearing did not fit the spindle. This is where I claim my own incompetence, should have tried the bearing on the spindle before proceeding especially considering the troubles with the sales people. Back to Northern Tools with a chip on my shoulder, this time I brought along a pair of calipers so I could give the so called trailer experts a lesson on measuring bearings. LOL I'm sure they loved being lectured on the subject. So I got home and guess what? In all the confusion I had lost the washer that goes behind the spindle nut. A trip to Ace Hardware and I finally had the parts to finish my 2 hour project after about 10 hours of dicking around.