lose one's wits

He wondered, going down the street, if it might not be a happier lot to lose one's wits like poor Eva, rather than have them to the full responsibility of steering one's self through such straits of misery.

His legs must have become suddenly feeble and helpless, and he felt a choking in his throat—you know the sudden feeling one has in moments of terrible fear, when one does not lose one's wits, but is absolutely powerless to move?