Not so.  They definitely lived family life until they were 18.

Most Catholic married people - if they're living their faith well - and haven't had an early death of a spouse have an N = 1 base of experience in marriage.

There's a myth floating around that married people are experts on marriage!!!  

They have statistially an infinitesimal amount of experience in marriage, one more than a (most!) priests. 

So you're wrong on that point.

Most priests if they're living their vocation well learn far more about how couples generally live or don't live married life than a married couple via spiritual direction, counseling and confession.  

They, unlike you, know the norms.

Besides experiences (as limited as it is for even one couple, given my earlier point) isn't the only form or even the most useful form of knowledge.