Yes, I think so too. Or perhaps instinct.
Ooh honestly, that might actually explain why he is so overprotective with him. Like he was really so sad in the past and maybe the regret that he failed to protect/save Hosik was etched deep in his soul that it manifested into an intense feeling of attraction and overprotectiveness in his reincarnated self.
Past life?? I didn't know that they showed their past life before lol. Can you tell me what chapter are you talking about?
I'm not sure if they both are. I'm sure Hosik doesn't remember it. But for Sunbae's case I am assuming that he does which explains his overprotectiveness towards Hosik. However, during their first and subsequent meeting in the campus Sunbae didn't show any sign that he knew about their past life. So I'm betting that it's just his instinct and guts that's driving him to that kind of behaviour (which i honestly love though).
Hosik has had dreams about it, but it has not mattered, it just seems strange to him. I don't know about Seunghyun.
Sungyeon is as possessive as ever... To be honest I didn't like him when he's first introduced. But after reading the Joseon era story, I wonder if he's like that bc he remembers their past life...