What was your biggest /facepalm moment?

At level 47, during a Directive 7 flashpoint that wasn't going well. I was told that my scrapper scoundrel wasn't a very good healer. I had been doing every flashpoint like this since hammer station...
(To be fair, in retrospect, I dont think healing output was the only problem in that group...)

Also, I thought not talenting into sucker punch would be ok.

/facepalm

I have 2 to mention.

1. Running hammer station on an alt, and tanking for a really bad group but, since they were clearly new, decided to stick it out. However, by the time we hit the last boss, I've started to get pretty pissy at our Mara for not following instructions and pulling out the (always embarrassing with hindsight) "check my achievements" argument. Anyway, I pull, point the cone attack away from the group, warm about knock back then, paying too much attention to the rest of the group rather than the job in hand, accidentally click a sideways step and am thrown off the edge by the first knockback! /facepalm

2. Huttball on my Sorc. About a minute left on the clock, 0-0, I'm on the upper ledge on the opponents side and the ball is thrown at me, I look ahead and the flames stop, clear run with no one between me and the goal line, I hit force speed.... misjudging slightly I run right off the edge of the platform and am torn apart when I finally land on the ground. Chat window lit up, most of the team having just watched that happen. All I could think to say was "I've never been very good at sports" /facepalm

I was playing an encounter area I had played before with another character. I recalled how difficult the fights had been with the old character. This time around I was beating the guts out of them and I felt like such a boss.......then I ran into into the empty elevator shaft and plummeted to my death.

My biggest facepalm came just the other day. I was looking through my screenshot collection and was apalled to discover that, according to the screenshots, my original character from two years ago (a DPS Assassin) spent the majority of the levelling process in the tanking stance.

What an idiot. Why didn't somebody say something?

I look back at my early days and facepalm quite a bit, even though I did unbelievable, stupidly well for all my mistakes. First off, on my Commando I used Hammer Shot way too often, and this is a habit that I'm now having to combat whenever I play him now, even at 55. Another thing is, when looking at my older toons (the aforementioned Commando, an Inquisitor, a BH) I notice that many of my Companions are wearing gear with stats that aren't theirs. Mako wielding an Aim pistol, Andronikos wearing a Willpower helm (), Elara wearing strength boots, etc. It's just a miracle, I guess, that I now know enough to begin repairing these mistakes, and play my newer toons with a far greater skill level (I can count on one hand the number of times I've actually died on my 34 Sage).

Plummeted to my death by leaping to that taxi platform on Coruscant.
Needed on an item the first time I grouped with someone.
Didn't understand crew skills at all on my first few toons. Only just learned about reverse engineering.
Bought a pack off the Cartel Market aimed for F2P on one of my first toons.
Accidentally bound an item of clothing, when I meant to just try it on. Done that a couple of times.
Didn't know I could unify colours until about a month ago. Been playing since July last year.
My first few toons and comps are so badly geared. One of the tanks had willpower stuff on.
Get lost everywhere. Even the Senate Plaza.
Tried to solo a flashpoint at level 10. Also tried to solo Coruscant world boss at roughly similar level.
Still can't get the hang of jumping - so can't get a lot of datacrons, and stuck on first macro binocular quest on imp side.

Such a numpty.

Been playing since beta but had an interesting moment on Tatooine. Playing through on my Vanguard I was running down a hallway thinking "W**...dead end". There was a strange object on the far wall so I kept running to investigate it...and plummeted about 3 stories. Sometimes I think the elevator shafts have a higher kill counter than some operation bosses

Well each class story is pretty much a constant facepalm moment.. many sidequests too whenever someone seems incredibly incompetent for their position.

Been there, done that. Multiple times, in fact. And not just the taxi pad. The most amazing time was probably in the Black Suns territory on Coruscant. Decided it would be cool to drive down the railing with my speeder, which worked perfectly... and then I miscalculated a jump.

Or that one time at Hammer Station, where I was totally sure I could still make it over the bridge. Or that other time where I forgot that the boss had a knockback.

a 2.4 scoundrel healer comes into a warzone with us, tells the team we got to protect him as he is doing all the heals (even though my commando healer and a sage are there too) and keeps talking about how he is the only good healer on the team and repeatedly calls us noobs and says the team should guard him more. When we lose, we look at the scoreboard, he has only done barely 200k in heals, whereas me and the sage easily broke 500k, and then he STILL keeps smacktalking even though we are pointing out the evidence to him. I literally waited an extra 5 minutes afterwards to make sure I did not get that guy again.