How did Brian make his fishing spear, and why didn't it work for him?

The spear didn't work because the fish were too fast.

He stood in the shallows and waited, again and again. The small fish came closer and closer and he lunged time after time but was always too slow. He tried throwing it, jabbing it, everything but flailing with it, and it didn't work. The fish were just too fast.

HOW DID BRIAN MAKE HIS FISHNG SPEAR WHY DIDN'T IT WORK FOR HIM

he isnt that smart