Exuberance

Wiktionary defines "exuberance" as "cheerful or vigorous enthusiasm". It's this latter definition that I'd like to think about a little bit more. Vigorous means physically strong or active while enthusiasm entails intensity of feeling.

Thus, exuberance is a "physically strong and intense feeling". This definition is awesome by itself, but it yearns to be paired with a different modifier. A certain Federal Reserve Bank Chairperson of the Board choose the word "Irrational" to accompany his "Exuberance".

For myself I choose the word "Youthful" as the preferred modifier for the word in question, thus "a physically strong and intense feeling of being young". Thus... "Youthful Exuberance". And fuck all y'all who don't agree.