What exactly makes the quarter century-crisis a actual "crisis?" Isn't it actually just the next phase of life?

So, in Growth & Development, we learned that not everyone goes through the "mid-life" crisis and it's only called that if it is a true "crisis" and it might merely be considered a mid-life "change" if it isn't drastic enough to be considered a "crisis." Examples of a crisis would be cheating on the spouse with a much younger girlfriend/boyfriend, buying a new car/boat that can't be afforded or wasn't discussed with spouse. A mid-life "change" would be simply changing clothing preference but still within the norms for the age group. Dressing in mini-skirts and getting jobs is considered a "crisis." We lkearned that the quarter century crisis is in fact real for some people. Needless to say, I fall into that catorgory extremely hard :-) right now, but isn't it normal and simply another stage in my life to be feeling this way? I don't have kids or a husband (already divorced) so of course when ever I get a baby shower or wedding invite it'll make me think of my own life, and yes, I've cut ties with some immature friends from hs/life but isn't this simply a stage in growth/development? What would be the "crisis" part of it? I'm in nursing school as well, so technically I've changed careers, but I've been in school for a few years already and am simply stepping up the nursing ladder since I am currently a CNA. How is my life in "crisis" as described by developmental theorists? (don't bother answering if you only know of the quarter century crisis as an urban legend on urbandictionary.com)