In an eight-hour day, the really effective working time averages about six hours  If a person does not work very hard, it is likely that the effective working time in a day is only four hours  But if another person works very hard and most of his mind is focused on work, even after work, his mind is still thinking about things at work, generating new ideas, thinking about solutions to problems, etc , at the end of the day, may be able to accumulate the equivalent of 12 hours of work experience, long-term, then two people work for ten years
The former may only accumulate work experience equivalent to six or seven years,but the latter already has the equivalent of 20 years of work experience
attitude