A million years ago when I sold things for a living, the phrase "attitude is everything" was doled out like roofies at an NFL after-party. It made sense, right? You can't control anything but how you approach what happens, so might as well be positive.
While there is truth in the sentiment, I eventually realized that it was a euphemism for, "This job sucks like nothing has ever sucked before, and if you don't want to end up curled in the fetal position or staring down the business end of a self-inflicted gunshot wound, you had better get with the maximum false enthusiasm." Many of my co-workers combined this advice with heavy drinking, drug abuse, serial adultery, and/or stealing audacious amounts of company property and cash. I opted to quit instead, got divorced (different story), and went back to college.
I was really just never any good at the fervor-on-demand thing. The best I could achieve was an "Eeyore on Plavix" vibe that just tended to confuse people. I managed my early career(s) with the strategy of proving myself smarter than everyone else, certain that they would eventually realize my inherent superiority and put me in charge of things. Every occasion that I was proven right, and no apology was forthcoming, I considered to be a personal affront, and another token for my necklace of petulance. I would tell all who would listen that my bad attitude was earned.
I eventually learned that, earned or not, churlishness was not paying off the way I expected. It turns out that people are less grateful having their errors pointed out than one might think, and nothing good ever comes of winning an argument with the boss. They like it even less when you throw it back at them later. I relearn this lesson almost daily, but I'm getting better at catching myself before I utter some synonym for, "Told you so," rather than wishing I hadn't said it.
I found it also helps immensely to work with people you respect. It's a bonus if most of them are smarter than you. It took me the better part of thirty years to arrange that. Now all I have to do is remember what it was I was hoping to accomplish.