Everyone has a jar with marbles. Some people are born with a lot of marbles, others with less (this is called "genetic predisposition").
Stress in our lives add marbles to the jar. When the jar overflows, you develop a mental illness. (Probably why so many soldiers develop mental illness in the form of PTSD after experiencing combat. That's a LOT of marbles).
Medication and counselling can help you lose your marbles. ;)
You can build a cap on your jar called "resiliency" by doing things to keep mentally fit like eating a proper diet, exercising, meditating and getting enough sleep; and not doing things that are risk factors like drinking, smoking pot (ironically, hard drugs don't seem to be a risk factor. Go figure), and not sleeping.
If you have lost your resiliency and your jar is overflowing with marbles, then you have a problem that needs treatment.
My jar recently became full, my reliency dissolved, and my bipolar disorder and anxiety flared up - badly. I am on medical leave right now as I work on losing my marbles. I started cycling rapidly between extreme hypomania and extreme depression (I have been going from bottom to top in one week, but thanks to treatment I have started to just be hypomanic - at least for the last few weeks). The hypomania can be pretty funny (and cause me to write lots of blog posts), the depression not so much (it's made me suicidal a couple of times in the last few months).
Here is a photo of what I was working on the other night while I was hypomanic and couldn't sleep, in spite of taking tranquillizers:
I stayed up almost all night working on this. When I get hypomanic, I work on things until they are done. My son came home from his night shift. After talking with him (I talk a lot when I'm hypomanic) I realized that this was crazy, stopped the project, and got some sleep instead of finishing it. It will probably stay unfinished, now, because the process was interrupted - and that's a good thing!
Mania makes your brain work in overdrive, until it finally becomes clogged with ideas. Some of the ideas are great (like my home-made aquarium filter that I built out of coffee filters, cheesecloth and charcoal), and many are bizarre (like my idea to create a cat food with things in it that will make a litter box smell nice. I named it "poo-pourri"). It also causes me to post too much on my blog.
So here's hoping I lose my marbles soon, so I can return to the work and a "normal" life. I hope you all lose some marbles, too. :)