Acheer once pressed Rabbi Meir with a hard verse: God also has set the one over against the other (Ecclesiastes 7:14). What did it mean?
Rabbi Meir offered the simple answer. The Holy One never made a thing without also making its opposite. Mountains and seas. Hills and rivers. Day and night. The world is stitched together from pairs.
But Acheer shook his head. His own teacher, Rabbi Akiva, had taught something stranger. God created the righteous and the wicked. He created paradise and Gehinnom. And every soul was given two portions, one in each. When a righteous person dies with merit intact, he carries off his own share of paradise and the share his wicked neighbor forfeited. When a wicked person dies, he drags down his own share of Gehinnom and the share his righteous neighbor was spared from needing.
Rav Mesharshia asked for scripture. The sages pointed to Isaiah's promise to the righteous, they shall possess the double (Isaiah 61:7), and Jeremiah's warning against the wicked, destroy them with double destruction (Jeremiah 17:18).
The Talmud preserves this exchange in Chagigah 15a. Your portion is never only yours.