Why do we not touch papers, books and people with the feet?

To Indians, knowledge is sacred and divine. So it must be given respect at all times.
Nowadays we separate subjects as sacred and secular. But in ancient India every subject -
academic or spiritual - was considered divine and taught by the guru in the gurukula.
The custom of not stepping on educational tools is a frequent reminder of the high position
accorded to knowledge in Indian culture. From an early age, this wisdom fosters in us a deep
reverence for books and education. This is also the reason why we worship books, vehicles
and instruments once a year on Saraswathi Pooja or Ayudha Pooja day, dedicated to the
Goddess of Learning. In fact, each day before starting our studies, we pray:
Saraswati namasthubhyam
Varade kaama roopini
Vidyaarambham karishyaami
Sidhirbhavatu me sadaa
O Goddess Saraswati, the giver of
Boons and fulfiller of wishes,
I prostrate to You before
starting my studies.
May you always fulfill me?