I thought that this might be a fun thread. Since I just made a big but harmless blunder. One of my coworkers called to switch days on me. This I knew. I print my schedules out at work by the week (usually two or three weeks in advance). I told my mom for the last three days that I was working today. I spent the past three days thinking that I needed to go to work today. Just as I was about to walk out the door, I decided to look at my schedule...and I found that I had hung the two separate weeks out of order! I'm off today! This was quite the blunder on my end; but I've never been happier to be wrong! Come on Y'all I know there's some of you out there that could relate!

That's a great mistake to make! A happy surprise, for sure. 
Mine wasn't half as pleasant, but it is something I can laugh about in hindsight. I always have to have a cup of coffee in the morning to get me through 9 am classes and, since it's fall and I had a huge jug of apple cider in the fridge, why not make apple cider coffee? I did some quick searches online and it sounded like you could just pour half a cup of apple cider into freshly brewed coffee and everyone assured me it would taste great! Needless to say, it tasted like something died in my cup, but at least I now know for future reference. 

FaithFighter : That was a good happy mistake. I wish mistakes like yours would happen to me more often.
kivdabe : Thank god I don't drink coffee anymore or else I would have to deal with drinking death in coffee. Thank you for the advice in advance.

I remember one time when I brought two gifts for two of my friends. I thought they would like the gift choices that I got for both of them. However, I somehow switched the gifts and gave the wrong gifts to both of my friends by accident. I didn't notice my mistake until one of them opened their gift. Not too fond with that mistake!

It didn't happen recently, but I've made the blunder of wearing my shirts inside out on accident when at home. I don't know how it happens... I get out of the shower, I prepare myself, then I put on the shirt. The previous times I did not realize they were inside out until roughly 2-3 hours later. One time I didn't realize for the entire day!

FaithFighter :
At least it wasn't the opposite blunder.... not going to work when you were scheduled to go! haha!

kivdabe : eeeeeewwww, that even SOUNDS gross! haha!  But I think I've done something very similar.... *whistles innocently*

You guys are really gonna love this one...  A month or so ago, I went to rescue my mom who was abandoned somewhere. I brought her home and got my dad to bring him to her car. After dropping my him off at the car site and making sure he could start my mom's car, I left on my way home......

WITH MY PHONE ON TOP OF THE CAR.

Luckily... amazingly... we heard it fall off the car about half a mile later and were able to find a spot on the highway to pull over. We searched for it and amazingly.... it fell RIGHT in the middle of the lane. Cars were zipping right over it, and my husband waited for a lull in the traffic to dash out and grab it.  By some miracle it was unharmed.

That was just a dufus move.

But you know what's worse?

I did it again yesterday.....

Well at least you didn't actually find yourself at work only for them to tell you that you were off! Lol!

I actually did something really stupid not too terribly long ago.. I was long boarding around town, and me being my stupid self still going down the road on my board I had pulled out my phone since I had received a message from my friend so I averted my eyes from the road and my surrounding, and not even 20 seconds later my board fell into a little pot hole and flung me off, causing me to scrape up and bloody my elbow, knee, and hand. I thought it was pretty funny when I had gotten home, though.