Do you see the center where the arrow is pointing? On a numerical graph that would be (0,0), which is also the vertex. Consider that that represents our known universe.
Consider that one of the lines in the diagram represents our previous universe, and consider that the other line represents love (life). When the love-line intersects the previous universe-line it creates a vertex where both of the lines are conjoined. Well, if the lines intersected right in the middle and created our known universe then that would mean that time existed both before and after our universe. The negative numbers behind the 0 on a number line represents the time that has already gone by (which is endless) before our known universe was created in the vertex. The positive numbers in front of the 0 represent the time that has yet to happen after the creation of our universe. If you look at this in a 3-dimensional perspective then the universe really is in the center and time and numbers do expand out in all directions.
That's just a symbolic example.