Reality & knowledge

Basically by working everyday, I have been occupied by many secular matters. Reality is always sever and therefore worthy to love.I tried to know reality through reading the books first and now I know there are many useless knowledges that don't apply to reality. But if people didn't read the books and knew reality first, they woudn't know whether some knowlegde they first encounter is uselss or useful. I can tell whether some knowlegde is useful or not.That's what I have been learning from reality.