Suicide at 49?

I was just reading about L'Wren Scott  who committed suicide a few days ago. And it hit me.. Why would someone commit suicide at 49? Shouldn't most of one's existential questions be answered by then? Why would you end a life at such a late age when you're already done with the most difficult bits?

But then I thought again. Why not? I mean having taken the most important part of the ride, why not get off when you're still on top? Who wants to live those last 30 years? Adult diapers? all sorts of pains in every joint, muscle and bone? Memory loss? And all the diseases and medication? People getting bored with you? Missing out on all the new technologies? Wishing to break free from an incapable body? Who wants those?

But then I thought again. Yeah.. Why not take those years? If I measure the increase in my comfort levels with who I am past my 30's and I extrapolate that for the coming 30 years, I can see myself becoming one of the happiest people in the universe. The speed of deterioration in one's mental and physical capabilities with age are much less than the improvement in one's comfort levels with oneself.

I see there are valid arguments for both. It's a personal choice. I just found it a bit surprising that at the age of 49, some people are still struggling with their existence.