Gout Attack - Normal Uric Acid Level

My uric acid level has been normal for the past two check-ups, or almost a year.  However, I still get sporadic gout attacks.   I haven't had a nasty one though since I've learned how to nip the attack in the bud, so to speak.  I drink painkillers just when the pain is starting.  The attack usually doesn't continue after that.

But why get the sporadic attacks when my uric acid level is normal?   My guess is that blood tests only measure uric acid in the blood and not the crystallized ones in my joints and the reserves stored in my fat.  Thus all I need is a temporary spike in blood uric acid to push the crystals into painful territory.  I guess that's why the pain lingers a few days after my badminton sessions.