Collectively, these results indicate that if there are associations between the Big Five personality traits and brain structure, they are likely of very small effect size and will require very large samples for reliable detection. (Little evidence for associations between the Big Five personality traits and variability in brain gray or white matter)
I like Buddhist reasoning on the mind better. Are you thoughts wholesome? Are they conducive to enlightenment? Are your behaviors wise and kind? Are you trustworthy? Do you trust yourself?
Be mindful of how your mind works as much as you can. Personality is impermanent, subject to change. Do your best.