You are influenced by your surroundings while also influencing your surroundings. The influence is mutual, it's just a matter of degree.
As long as you exist in society, no matter how reclusive you are, you can't escape society's influence. Do you think that fleeing to deep mountains or isolated islands can sever such ties? Even in midnight dreams, aren't you still haunted by past pressures, unable to help yourself?
Ishida Hideko, however, is a person within society, yet an outlier.
Severing ties doesn't rely on distance, but on insight.
Coarse cloth changes color in a dye vat, while stainless steel maintains its sheen for a long time. True nature, eternally existent, naturally cannot be dyed by any extraneous matter. Hence, Buddhism uses the five aggregates to describe this state.
The Sixth Patriarch's "originally there is not a single thing, so where could dust be attracted" is a true interpretation of this nature.
