Before he was part of BTS, j-hope (artfully lowercase) was a street dancer. He is quite a skilled dancer, and learns in minutes choreography that takes others hours. He only began rapping after joining the band, and said he learned much from the other members at the time, RM and Suga.
j-hope is very cheerful and is quite a mood-maker. His name is inspired by the story of Pandora's Box, in which hope is the only thing that remains after everything evil is released into the world. On talk shows and at concerts, he uses the tag line "I'm your hope, you're my hope, I'm j-hope" to introduce himself. He often acts humorous at his own expense to help the members lighten up in stressful situations. However, sometimes it appears that he feels the pressure of staying happy for others' sakes.
Despite his sunny demeanor, j-hope becomes very strict when he coaches the members on how to dance. I believe he once made them cry.
j-hope released a mixtape in 2018 called Hope World. The songs describe his pride for his group and reflect on how far they have come. He also raps about the human behind his cheerful exterior.
On the meme side, a video of BTS reacting to their own performances soon rose to meme fame because of audio of Suga screaming "J-HOOOOOPPPPPPPPEEEE" at on-screen j-hope for, it appears, absolutely no reason. As it stands now, several comments on j-hope related videos are often just "J-HOOOOOOPPPPPPEEEEEEE."
Overall: hoseok is everyone's hype man. we love him.