沵是莪最大的谎言
[mĭ shì é zuì dà de huăng yán]
These characters phonetically sound similar to '你是我最大的谎言'(you are my biggest lie) where '沵' stands for '你'(you), '莪' for '我'(I/my). In context, the owner acknowledges some important thing in life turned out to be untruthful or deceptive. Perhaps, it also indicates a sense of guilt from lying repeatedly, eventually becoming self-deluded about truth.