What does it mean when a generally happy and ambitious person has lost all interest in existence?

Answers

Bela

It means they're depressed and should probably see a doctor.

Ian

Have you finally seen the real world?

KTJoe

Means person has found something else to occupy his mind.

ravenhill the blacksmith 1043A.D

it probably means this modern life has beaten them down.

Sandy

they put their best face forward, but behind the scenes they are depressed and suicidal. that's really who they are. they need medical and psychological help.

sats

It means that life doesn't come with a dancing clown that is supposed to make us happy all the time. Sometimes we are up and other times we are down.

Pat the cat

Depression.