grandiosity An inflated appraisal of one's worth, power, knowledge, importance, or identity. When extreme, grandiosity may be of delusional proportions.

Grandiosity An exaggerated belief or claim of one’s importance or identity, manifest by delusions of wealth, power, or fame

I was diagnosed as a narcissist by one psychologist:

While grandiosity is the diagnostic hallmark of pathological narcissism, there is research evidence that pathological narcissism occurs in two forms, (a) a grandiose state of mind in young adults that can be corrected by life experiences, and (b) the stable disorder described in DSM-IV, which is defined less by grandiosity than by severely disturbed interpersonal relations.

The grandiosity label arose from my belief I could change the culture of the law firm I worked for. I was the managing partner and had big plans. The other partners thought the status quo was fine. The disappointment I expressed became a lesson -- good ideas need to be sold and do not succeed without some consensus. My consensus building failed, even though I thought I had the support of the other partners.

I do or did exhibit some symptoms of narcissism. I no longer have the diagnosis.