Everything we learn in school is usually one-way communication.
Teacher teaches, student learns.
The more knowledge a teacher shares, the more knowledge a student learns.
In spirituality, it is a bit different.
The knowledge is already inside. Locked up and hidden. The teacher aka Guru comes about, and unlocks the hidden knowledge.
But for this, the Guru needs to be allowed near the student. Not necessarily physically, but especially mentally.
If the ego is a big wall, then no one can come near, not the Guru, not even God.