What 2 reasons does Shakespeare's give for wanting his beloved to forget about him?

One reason seems to be that the narrator doesn't want his beloved to feel the pain of loss, "If thinking on me then should make you woe."

There is also the sense that the speaker may not have been such a popular guy so he doesn't want his beloved to be mocked when showing grief, " Lest the wise world should look into your moan And mock you with me after I am gone."