Only one thing that has been itching me in the 2nd story - isn't it weird how the kid's fe...

Only one thing that has been itching me in the 2nd story - isn't it weird how the kid's feels for his absolutely random stalker (sunbae) went over the hills in literally no time? He was so creeped out at first (which was normal) and he barely knew him at all. But within a few days he's all drowning in overwhelming love and feels for the dude like - I know human mind works in a very illogical way but still it's so sudden and weird! Like something feels fishy I dunno why "-"