In this sonnet by William Shakespeare, the speaker "bewails" (mourns or shows great regret for) his past and present. Looking back, the speaker summons "up remembrance of things past" and regrets that he was unable to achieve the many things he wished for. According to the speaker, he wasted time that he cannot get back: "And with old woes new wail my dear time's waste." The speaker goes on to mourn the lives of his friends who were lost in "death's dateless night." He continues to weep because remembering them has brought the pain to the surface.
Therefore, the speaker bewails a life that did not come to be as promising or fulfilling as he had hoped. He was unable to do everything that he wished to do, and now he finds that it is too late. Looking back on his losses only makes the speaker feel the losses again.