(Not OP, but interested to hear more)

In terms of motivation, do you know of a way to begin a sincere and genuine interest in others that doesn't have some ulterior motivations? That may sound kind of mechanical, but what I mean is roughly something like: "I don't know people, so I do not have any 'genuine interest' in them. As a result, any interest that I do have is insincere."

I chose not to have friends for several decades, which has been extremely convenient for the most part, except for tasks that require more than one person, or work-related situations. Not having to worry about offending people, remembering birthdays, messing up my own plans for the needs of others, etc. was very burdensome. However, being able to use people as a job reference, or getting leads on future opportunities from people I used to work with would also be beneficial so I can understand why people would expend the effort. However, retaining a friendship solely for those job-related purposes seems grossly manipulative because there is no sincerity in what I want from them. I do not want them I only want to extract what they can give to me.

Is it simply understood that, if you make friends with someone as an adult, it is inherently with ulterior motivations in mind, whether it be to avoid loneliness, get work-related benefits, or extract knowledge from them? As a child, I think people tended to make friends simply because they were bored and the person seemed neat. Is that why people still try to make friends with people?