There are two main shift that happen in Patrick Lane's poem "Because I Never Learned."
First, the poem represents a definitive shift in time. The poem is broken into two stanzas. The first stanza represents a time where the speaker was young and growing up.The second stanza represents twenty years later in the life of the speaker. This is the first shift depicted in the poem.
The second shift is more hidden. In the first stanza, the speaker recalls his father's mentality regarding life and death. For the father, death seemed to be nothing. He, and his son (assumed given the male author), were surrounded by "dead animals and men." Death seemed as normal as breathing.
In the second stanza, the speaker has taken his father's thoughts on death as his own. The speaker, much like his father twenty years previously, now regards death in the same way.
In the end, the second shift which takes place is the transference of thoughts about death. The speaker "never learned" to be sympathetic about death.