have you ever just up and walked out of work? and never returned..?

Yes, I have. A couple of my co-workers tried to get me to stay, but I was sick of the job. I'm sorry I did it, because I couldn't use them as a reference. It's better to give notice.

Yup. I just got up and walked out. Granted, I was also 20 and didn't give a hoot. I can't do that now, but luckily I don't hate my job. I just escape on here sometimes when it gets too crazy.

You have to think long and hard about the consequence. If you have money saved, ok, fine and dandy, but map out all your bills and make sure you can keep yourself afloat. The "responsible" thing would be to try and find another job before you quit your current one.

Trust me, I know how hard you want to tell the boss to kiss you butt and walk out and never come back, just be sure that you CAN. I also understand that if you can no longer take it, you shouldn't feel like you have to. If you want to walk out, do it, have courage, and be well.

Yes I have. I was a bartender at the time at a horrible place with horrible, rude owners who treated everyone like crap. One of the owners came up to me and the other bartender, with a full bar, and started screaming at the top of his lungs how we were horrible and worthless... Not for anything we'd done... It was because the servers, on the other side of the room, hadn't gotten to a table fast enough. This literally had nothing to do with me or the other bartender, we had no idea what happened on the other side and were not the bosses of the servers. So I grabbed my stuff, and left. It was a fantastic decision, and the other bartender did the same. They went out of business 3 weeks later!
I wouldn't normally recommend it, but sometimes it's the right choice.

No, I haven't. I made it through an entire career without coming close to that.

Yes. I had an emotional breakdown at work. It was a long time in coming. I was actually getting boils- literally, those skin irritations that break out on your skin. It was scary. I was under so much stress that I could barely take it. It wasn't always that way. I mostly began a month or so before I left. I had been promised a promotion by the manager of my department, then on the day he was supposed to make his recommendation to the superiors, he called off. They gave the job to a new hire, who did a horrible job, btw. Another coworker started doing work that wasn't her responsibility, basically pushing me out of my job, and when I complained to her, she told me in so many words to F off. She was a control freak, and rubbed many people the wrong way, but as is with me, I can't keep my thought to myself so I told her to stop being so pushy and she retaliated. Then in a completely unrelated incident, a guy I had to work with starting using racial slurs about my group, so I was at my limit. I saw one worker commit a blatant and very gross health code violation. The others were even talking about it. I discretely approached the manager and told him, and since it was an 'old boys club' kind of place, he rebuffed me, saying that he had never seen such a thing take place. It turns out that another coworker had actually made the same complaint I did, but the boss didn't care. On my last day, when the boss was on vacation, the temporary boss (one of my senior coworkers) said something offhandedly to me which was quite insulting, and I shouted back at her. Everything was dead silent, because most of them hated her and were doubtless interested in how she would react. She was speechless. Probably I could have stayed on, since I don't think anyone would have taken her side to the boss, but I had just reached my absolute limit and walked off the floor, never to return.

Yes. I told my boss a few days in advance that I could not stay late this one day because I had a mid-term and could not take the later bus. They insisted I stay "a few minutes" late, so I did and ended up missing the bus and failing the mid-term. I called to quit the next morning without ever showing up again.

Yes. I just walked out, called up my boss and told him I was done. At first he thought that I was joking. I wasn't. Then I moved back in with my parents before getting a new job.