Well, I am an indigo, at least I've been told so by several people who can see auras. They told me without my ever asking or even knowing what it was.

I learned something more about indigos then and the description definitely does fit me a lot. Even though I've never had the slightest trouble in school (apart from hating it vehemently despite having excellent results).
I've also never been even suspected of having ADHD.

To me this indigo thing is like learning about whether one is extroverted/introverted, brain hemisphere dominance etc.
It's nice to learn something new, it might help me understand certain things about myself or meet people who might be dealing with similar issues.
But that's about it. I'm definitely not building my identity on that.

I can see where you're coming from though.
I also find it somewhat strange when people immediately talk about meeting their twin flame whenever they are somewhat attracted to someone or go through the dark night of the soul whenever they miss their bus in the morning or experience any other inconvenience of similar significance.

But that doesn't mean those concepts don't actually exist.
Just because some people misuse them, try to fit them to their situation at all cost or use them as an excuse for their shortcomings doesn't make them invalid.

I don't know, I just always prefer to keep an open mind and so claiming that something simply doesn't exist always sounds to me a bit like...doing the exact opposite.