前面说的都不错，但limbo会“永远”？

现实苏醒是可以的，只要镇静剂啊麻醉剂失效就可以了...哪能一直睡...
但是这样的“自然”醒来，人会恍惚而失忆...植物人不至于，傻乎乎的倒是真的...

其实电影的原台词都说明了...

相关台词也就是这些了，看看怎么理解算是原意吧...

ARIADNE
And if he dies?

COBB
His conscious mind will drop out of the dream. He'll be trapped in Limbo for a lifetime...

ARIADNE
What will that do to him?

Cobb looks at her. Grave.
COBB
When he wakes... his mind could be completely gone.

SAITO
When... when we wake I will still honor our arrangement...

Cobb looks down at Saito sadly.
COBB
Saito-san, when you wake you might not even remember that we had an arrangement. You'll have forgotten this world. Limbo will be your reality. Lost there so long, you'll have become an old man...

SAITO
Filled with regret?

COBB
Waiting to die alone. Yes.

SAITO
Then I'll take the chance and come back. And we'll be young men together again