I believe 당신 can yes; even if 당신 don't know them 또는 see them, if they've impacted your life in someway 당신 can miss a feeling they gave 당신 (eg a TV character that can make 당신 laugh) and when 당신 get the feeling again it can make 당신 think of that person.
Hope that makes sense but that's kind of my idea of why I think 당신 can miss someone.
yes,it's possible to miss someone you've never met.I miss my fave movie characters and movie celebs who died(like Paul Walker) and even some 동물 that died 또는 were killed(like Cecil,the lion from Africa)
Yes, I think so. Like celebrities, who are still alive 또는 who have passed away. 또는 fictional characters from Tv shows who have been killed off 또는 just left, 또는 anyone I suppose. I mean, I miss a couple of celebrities, who have passed away like Heath Ledger, Cory Monteith, Brittany Murphy, etc. So, yeah, 당신 can.
Yes. asides from fictional characters and actors 당신 like, the internet provides a good 출처 of that. Like how 당신 can miss an online friend 당신 haven't chatted with in a while, even if you've never met that person in real life.