It's one of the less funny 4chan memes Fur...don't worry about it lol I never found it funny either and I'll laugh at just about anything :p It started out as Duckrolling people by linking to another thread within an unrelated thread, and the link led to a picture of a Mallard duck with 4 wheels instead of feet, aka duckroll. Then some dumbfuck thought taking it a step further and linking to Rick Astley videos when claiming it was something else would be funny, and it caught on sadly.

I miss the good ol' days when /b/ made GOOD memes, not the shit they spew(like rickrolls and raids) nowadays :p

(And trust me, if you dunno what 4chan is you don't wanna know; save your sanity.)