曼德拉在监狱期间鼓励自己的诗歌是《Invictus》，这首诗的内容如下：

```

Out of the night that covers me, Black as the Pit from pole to pole,

I thank whatever gods may be For my unconquerable soul.

In the fell clutch of circumstance I have not winced nor cried aloud.

Under the bludgeonings of chance My head is bloody, but unbowed.

Beyond this place of wrath and tears Looms but the Horror of the shade,

And yet the menace of the years Finds, and shall find, me unafraid.

It matters not how straight the gate, How charged with punishments the scroll,

I am the master of my fate: I am the captain of my soul.

```

这首诗出自英国诗人威廉·埃内斯特·亨利（William Ernest Henley）的作品，曼德拉在狱中读到这首诗后，深受触动，并在此基础上创作了《成事在人》（Invictus）这部电影。