You won't necessarily find yourself happier - it's a choice. If you go right back and make the same mistakes at a new job, you'll hate that one too.

I got fired a few months ago and it was the best thing that could have happened to me. Until then, I'd changed jobs every so often because I never liked where I worked. But when I got fired, I thought long and hard about what I needed in a job. Only after acting on some well thought-out conclusions did I find an excellent job that's absolutely a perfect fit for me. I probably wouldn't have thought that hard about my next step if I wasn't fired.

So while that comment is true for me, I can't imagine that it's always true. If I was a dumbass and took a job exactly like the previous one, I'd hate that one too. I might not get fired - I might quit before they fired me. Honestly it doesn't matter which happens first. If you don't put in the introspection to find a place that fits you and vice versa, you'll hate it in no time.

Figure out what you need, figure out what you can do well, and find a job that matches that.