The reason the incel is single is because he doesn’t put the effort into not being single. This is what he decides to tell people when the topic comes up. Realistically, he can’t imagine a situation where he would have to justify himself like this, but at the very least, he has an all-encompassing answer to his dilemma that can be broken down into a logical hierarchy.
What does putting effort look like? In the incel’s case, he needs to break free from years of self-loathing and learn to love himself, as well as physically be around more people (statistically speaking, cast a wider net). People that genuinely love themselves naturally strive to be the best they can be; in other words, the good looks and charisma he strives for come automatically.
So how does the incel get this elusive unconditional self-acceptance? That’s where his confidence in this plan starts to fade, and where the physical, visceral manifestations of his negative thoughts start revealing themselves to him in the form of uncomfortable stomach and chest contractions. He could continue attempting to change his negative thoughts as he recognizes them, and if he wanted to go nuclear, he could steer clear of toxic message boards and other havens of self-depreciation, but in the end, he might benefit from professional help. The difference between now and his last therapy session many years ago is that he has a specific goal to work towards this time around.
But as optimistic as the incel wants to be, he can’t help but fret about his sudden interest in fixing himself. In a perfect world, he would be facing these tough situations purely for the betterment of himself, but in reality, he just wants to have sex. Meticulously stressing over every move he makes, as if life were just a long dating simulator purposely rigged against him, ambitiously and desperately attempting to break free from his supposed predetermined and pre-programmed inadequacy, didn’t work (who would’ve guessed haha), so he is left with no choice but to go the slow, painful route that’s guaranteed to work - self-improvement. His intuition tells him that, ironically enough, true progress in getting women will not be made until he stops making everything about getting women in the first place, but rather makes this about fixing himself for his own sake and for no one else. His coworker has reassured him of this - desperate men aren’t cool.
Another action step the incel can take right now is avoiding self-pity. Now that he has reached a point in his personal development where he can dissect his own negative values and beliefs, he admits to a morbid, masochistic comfort in reinforcing these negative emotions. He passes through daily life so lipid and lifeless, that any intensity in the sea of gray seems valuable and worthwhile just for the sake of feeling something. His stomach ties itself in a knot and begins to sink into his ribs, and he feels at home.
A good thought experiment to keep himself in line and get some perspective is a mental regex substitution of what his goal is. Let’s suppose that instead of having high ambitions to have sex, they were instead high ambitions to be a millionaire. Does it make any sense for him to want people to pity him for not having been magically endowed a million dollars, all the while doing nothing to get him physically closer to that goal? He’d get slapped across the face because the idea is absurd! Sex is no different. Sex is not a right, neither a reward from above for being a good boy, or more accurately, for not being evil (the absence of evil doesn’t necessarily imply good).
In short, the recovering incel refuses to go back to his old ways, and instead looks for real solutions.