Because explaining the joke always makes it funnier, here is the background information to get the joke.

That is Quentin Tarantino the director. Due to some of the shots he has included in his movies most fans of his movies assume he has a foot fetish.

In BJJ in a gi most submissions of the feet and legs are against the rules until a very high rank. In no gi those submissions of the lower body are permitted for everyone.

So the joke is that I was walking in obsessed with feet and planning to only work on those submissions that are banned in gi classes at my rank.