Sonnet 116 is one of the most famous poems written by William Shakespeare. In this sonnet, the speaker defines true love as constant and unchanging, regardless of external circumstances. The poem emphasizes that genuine love remains steadfast through challenges and does not waver with time. The speaker argues that true love is not affected by physical changes or obstacles. If love can be altered or diminished, then it is not true love. The sonnet concludes with a bold assertion that if the speaker's definition of love is proven wrong, then no one has ever truly loved.