No job for life

'No job for life' - saying that appeared on CAE speaking. How would you explain it? I've got problems..

So have I, because there are no jobs for life anymore.

there is no job you could do all your life, until you retire

Just a guess

or
you aren't forced to keep working where you work until you retire. You can change jobs.

...not so much 'forced' as have an unwritten guarantee, that you can carry on in the same job until you retire.

quite the opposite of what I thought (blushing), thanks!