This is a work of fiction set in a comic book style world.
This is currently a work in progress.
How does one know that they're a mad scientist?
Take Phil. He toiled away in secret because all of his colleagues laughed at his work. He believed he was helping the world, and really wasn't hoping for monetary gain or power; just a bit of fame (what little fame the unwashed masses would give to a biologist), and a chance at immortality.
He couldn't make money off of his work, anyways, unless he won a Nobel Prize or some other award that came with a cash prize. Once released, there would be no way to contain his experiment; it couldn't be bottled and sold. The first person who gets the treatment will be contagious in a day, and continue to be contagious for the rest of their life.
And that's why we're asking how someone knows if they're a mad scientist.
Phil clearly remembered the look in his labmates' eyes when they realized what he was working on... A mix of wonder at first, giving away to terror as the full implications hit. A week later, after a rather long talk with the lab's director, Phil was painstakingly taking notes of his processes as he ceremoniously destroyed the initial fruits of his labor, tears streaming down his face, teeth held tightly closed.
His labmates didn't notice an unmarked styrofoam cooler near Phil's desk, and didn't think twice about leaving that day promptly at 5pm as they always did, despite Phil still pouring over his notes, slowly erasing the physical results of his experiments. He didn't get to save much, but he saved enough and had just enough equipment at home to finish his experiments, thanks to his colleagues trusting a charismatic, promising young man and having their own habits and own concerns to distract them.
The work was slow. Phil no longer had a supply of human stem cells to work with, as he did at the company lab. He couldn't buy the specialty growth mediums, either, and relied on agar for most experiments, and brewed his own when the experiments called for it.
After the first couple of weeks of depression, the only change in Phil at work was his insistence on wearing long sleeved shirts under his lab coat. These hid the needle marks, what junkies and narcotics officers call "tracks," that marked where he had been getting samples for his experiments.
Nobody outside the lab learned about Phil's transgression. It was enough for the researchers to keep their heads down and stay out of headquarters' way, as the corporate level managers were far more focused on the founder's pet project, a man-portable radiolytic thermal generator (RTG) that worked on fusion. The fear was that if word of such an experiment leaked out, funding would be cut to make way for more research into the fusion RTG.
Did Phil know that the world would consider him a mad scientist? Perhaps. He certainly had the sense to keep quiet, and he had the dogged determination to finish his project no matter what the costs. At the same time, though, Phil honestly believed that he was doing real good in the world.
After Phil's sacrifice, though, we may never know what he truly thought of himself.