Does the word "sailor" mean that a person can swim? And speaking of swimming, can you learn it by grinding your horse stance and performing idealistic land exercises?
Then, to decide which moves are blocked by Black's own pieces, you take a bitboard of all of Black's pieces, take the complement (the NOT operator) and then AND it to your knights' moves bitboard.
Then, to decide which moves are blocked by Black's own pieces, you take a bitboard of all of Black's pieces, take the complement (the NOT operator) and then AND it to your knights' moves bitboard.