A better mousetrap
The other one is right, of course, to caution about premature fixation.
I have always thought fixation is like a mouse trap. It has both a triggering mechanism and an arm of destruction.
The trick with mouse traps is to make sure that the triggering mechanism is sensitive, but not too sensitive. The other trick is to have an efficient re-arming mechanism.
If fixation is like a mouse trap, then mine has a somewhat erratic trigger and is a complete bugger to re-arm.