E.E. Cummings' "[i carry your heart with me (i carry it in]" is a narration of a speaker who loves the object of the poem, and his entire existence is actually defined by this love. Carrying the lover's heart implies the speaker recalls this love whenever he does anything.
The lines in the first stanza of the poem, such as "i am never without [your heart] (anywhere i go you go, my dear," showcase how the lover exists in everything the speaker does, even when they are not explicitly together. Furthermore, the tone of the poem is mostly confident and accepting; he understands this love, he admits to this love and he is at ease. According to Schmoop.com, the speaker's tone reflects both his love and the idea that, through this love, he is "at peace with the world and everything in it."