I just made a bonehead move the other day. I was booking a trip for my SO and I to fly into FLL. I have a business trip that I am staying on for, but he is flying with me for the weekend and will return on Monday morning. Plus I had some credits sitting on WN so I figured I would book us both on there, but had to book them separately because of the different travel dates and because my company is paying my ticket.
Anyway, I open two browsers and proceed to determine what flight to book us on. We talk back and forth to determine if we should leave work early or take a later flight and we finally agree on and I complete my SO's reservation for the earlier departure. I get called away from my desk for a minute and go back and finish my booking. Well, dummy me - I forgot we picked the earlier flight and I booked myself on the later one. Fortunately (one of the only good things I can say about WN) is that the earlier flight was cheaper and you can change the flight easily. I ended up with another credit in my account and got myself on the right flight!
Ok, second dumb move - I was going on a cruise with kids, SO and his mom. 5 people, 10 suitcases, 4 carry-ons. (Yes we over pack) Land in Puerto Rico, and while scrambling to get the bags, kids have to go to the bathroom. SO takes them while I collect the bags. Get to the ship and start unpacking only to realize I have no shoes. I scratch my head then realize there was one suitcase with all shoes. I go to call JetBlue and see that I have already have a message from them. I apparently lost count of the bags and I left my one suitcase on the belt when we arrived. Fortunately we sailed late that night, so I grabbed a cab, went back to the airport to retrieve the bag and returned to the ship in about an hours time.