Being self aware of mental disadvantages

[VariousRen]

If a character has a metal disadvantage, how aware are they of that disadvantage, and how much can they do to prevent that disadvantage from coming into play?

For example, if I have a mage who has pyromaniac (SCN 15) does he realise that learning fire spells is a bad idea, and would he have to make a self control roll to turn down the opportunity to learn fire spells? Or, on the other hand, can the mage purposefully avoid fire spells to ensure that his mental disadvantage comes up far less often?

Another example would be curiosity during a long over land trip. Would the curious PC be allowed to willingly lock themselves inside a carriage with the windows blocked in order to avoid being drawing towards investigating things as he travels?

My first instinct is that by default people are aware of their mental disadvantages and can take steps to avoid them coming up (avoiding curious things, not learning fire spells, ect). If someone wasn't aware of their mental disadvantages, they would have delusion (I don't have X disadvantage), with the severity of the delusion based on the severity of the disadvantage.