In life, the number of beginnings is exactly equal to the number of endings: no one has yet to begin a life who will not end it.
An act of the mind. To move, to make happen, to make manifest. Be an act of Congress. A state of real existence rather than possibility. And poets love possibility!
I believe many fine poems begin with ideas, but if you tell too many faces this, or tell it too loudly, they will get the wrong idea.
I have flipped through books, reading hundreds of opening and closing lines, across ages, across cultures, across aesthetic schools, and I have discovered that first lines are remarkably similar, even repeated, and that last lines are remarkably similar, even repeated. Of course in all cases they remain remarkably distinct, because the words belong to completely different poems.