I keep confusing 兴 xing4 (happy) and 光 guang1 (lustre).
光 guang1 is a man 儿 carrying fire 火 - light -- lustre. Remember, the bottom part of 光 guang1 is "man".
兴 xing4 in its traditional form 興 is composed of 舁 yu2 hands lifting and 同 tong2 together -- happy. Remember, the bottom part of 兴 xing4 is "hands".