Journey Concert -- SURPRISE ... No Underage Boozing Arrests

The word "duh" has never been more appropriate ... because cops in Chula Vista say they didn't arrest one single underage drinker Thursday night at the Journey concert.

It's unclear if the statistic was a result of the CRACKDOWN cops called for to prevent kids from boozing at the show ... or, more likely, there just aren't underage people hitting up Journey concerts to get wasted these days!!

Officials did say there WAS a large number of people under 21 at the Sleep Train Ampitheatre last night ... so, whatever the case ... SUCCESS!!