I purposely made this question generally broad so that it can apply to more people in need of similar interpersonal skills, but I can easily make it about a specific scenario if needed.
My whole life, people have put me on a "genius" pedestal, and while it was a fun ego-booster when I was a kid, today it's more of a curse than a blessing. I don't see myself as a genius, but others do. The problem with that, as you might imagine, is that they'll assume I have solutions and answers to a lot of their problems, even if I'm completely ignorant/indifferent to the subject. What makes matters worse is that often it's about something related to some subject I'm known to understand well. So when I try to address that I don't know about the matter, people sometimes become infuriated/frustrated as though I "don't want to help" or am doing it "grudgingly". What they don't seem to understand is that I do want to help, I just don't know how. I try to help when I know, and when I don't, but it's within my reach, I do look up how to help, but they see it as me "not wanting to share the knowledge that I have". This usually happens in my family, but sometimes friends also have high expectations from me. Most of the time, the same people make such accusations multiple times, in spite of me telling them about my lack of knowledge for the Nth time.
One example where this happens: I'm a full-time programmer, and also work on all sorts of computer-related projects in my spare time. However, I don't know a thing about hardware stats/brands, or how to do stuff on Facebook (I don't have a Facebook profile). Yet, people often respond with "how come you can do X, Y and Z on a computer but not know how to pick a piece of hardware?" or "you know how to X but you don't know how to Y on Facebook? At least admit you don't want to help!". Keep in mind that it's not that I don't want to help them - be it a tech-related issue or otherwise. It's just that I cannot help them because I'm not informed enough on the subject. People asking me for help don't bother me - when I do know, I help however I can.
Another example (since the IT example got more attention than I actually intended): someone asks me about some math-related problem, or about a word, expression or sentence in English I've never seen before. If at any point I state that I don't know how to solve it or what it means, I'm met with accusations such as "of course you know, you studied English for N years" or "you're super smart, of course you can solve this simple problem". The fact that I might know something relatively more complex makes it even hard to defend my case, because if I can solve this complex equation, then surely I can calculate this simple interest formula. I do look up solutions, but even still it's frowned upon, as if I were "pretending not to know" and "excusing myself by grudgingly searching it". The mentality is flawed on many levels and I fail to comprehend how one comes up with such notions, but that is already beyond the scope of this question.
How can I respond or act when accused of knowing something I don't, when admitting ignorance is not enough? Ideally, I'd like to be able to assert to people that I am in fact ignorant on some subjects. If that proves to be too difficult, then minimizing conflicts against people's expectations would be my desired outcome.
What I have tried
- Stating I don't know about the subject because I never looked into it: doesn't work most of the time, will just get dismissed as me being "unwilling to help";
- Stating that, while I don't know about it, I can look into it/see what I can do: often will just result in an angry "if you're going to grudgingly do it then don't even bother", which I don't know how to respond with, since I'm clearly showing willingness to help regardless of my knowledge of the subject;
- Pretending I know about the subject: doesn't work, backfires easily, and I don't like lying;
- Arguing with the person, trying to convince them I don't know everything: doesn't work with some people, apparently I'm too smart not to know everything there is to know in this entire universe or something;
- Ignoring the person accusing you of withholding knowledge: works most of the time, but is just as stressful as arguing.
A lot of people understand I might not know something, but still, some individuals (a couple of them easily come to mind) still cannot fathom how I might be ignorant about something I "obviously" should know about. I tried sarcasm, long and in-depth explanations, rudeness, or just outright playing deaf, but the problem keeps reoccurring.
I'm adding a cultural background tag, but any approach is welcome at this point.
EDIT: There seems to be an ongoing theme in comments and answers advising me on how to avoid helping people, or how to have people help themselves, or how to ignore them. These would make (or have made) great questions, but it's not related to my issue: addressing people about a misconception they have about me, in that "if I know A then I must know B" when, in many cases, that is not true at all.