Achieving work-life balance is very important. A person without such balance is on the fast lane towards depression.
A few misconceptions should be cleared out first: 'work' and 'life' are not opposites - work is part of life. Many people see the 'work' part of their lives as a necessary sacrifice to sustain the 'non-work' part of their lives. This kind of polarization is not very helpful in the long term.
When work-life balance is disturbed people tie their identities to their work or their job titles, and they start measuring their self-worth by either the amount of money they earn or the amount of money they spend. It can be quite difficult to escape or ignore a social environment made up of such people.
The secret to work-life balance is to put 'work' back into 'life'. Consider your long term plans, and determine how valuable your time is after a certain level of income. Set up gradual goals. When you put things into perspective, you can more easily start enjoying the 'work' part of life as well.