Actually, if you are going to play someone with an interesting quirk, like insanity out of the norm or age or certain strange origins you should apply for it no matter how minor it is. Not because you have to but because it is the right thing to do. When you apply for it, you alert the admins of your intention and clear the way of any misunderstandings you could have in the future and any troubles or violations you may experience in gameplay. It also gives the admins a history of your pc and shows that you are dedicated to your rp and want to do certain things to help that rp. And it might also tell you the cost of that rp such as kismet costs and such, here is the helpfile
Special character and special roleplay
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If you wish for your character to have something that is not the norm then
you must apply for it. You should detail your characters information to the
applications committee.
Your application is put before the deities for a vote. The more information
that you give the better. Try and be consise with a summary of what you want
as sometimes what is really wanted can be lost in rambling.
Send applications to
applications@forgottenkingdoms.com
Please note that players with strikes on any of their characters are not
eligible to apply for special roleplay applications.
Most special roleplay applications will incur a kismet cost. We will
likely not approve any applications that focus only one one character
that require alot of work on the part of the immmortals to implement.
We are not at this time taking applications to follow gods who are
not coded into the game.
See also: help SPECIAL POWERS, BABIES, TWINS, SIBLINGS, KISMET COSTS.
No matter how minor a change is, it does not hurt to apply for it. Because it might become major. It saves you from later troubles and tribulations and adds to your character's history.
Ellian, though it might not seem neccesary, it can be become important later on or in case you wish to add more spectacular quirks of character to another pc in your collection. It never hurts to practice and learn what should be applied for and what does not need to, I see it as a set of guidelines that help you hold to your rp or expand on it.
And always, be patient while the application is being processed, use that time to explore your character and the decisions fully and use that time to decide if what you are doing will work for you. Even if you have a firm decision it never hurts to think about it more and to consider how you will approach your rp.
Thanks for the advice Gwain. You too, Ellian. 
This'll be so much fun!