Indigos and soul age

Maybe I misunderstood something along the way, but I thought that Indigos were supposed to be older or more mature souls.  But, according to Gunny, our Indigo friend is actually pretty young.  This is really confusing to me.  I mean, Carrie is an Indigo and also old in soul ages.  And in general it seems like Indigos are older souls.  But maybe that’s not actually a requirement.  Perhaps the role of the indigo can be filled without as much age as I expect?  I don’t really know.  It’s something I’ll have to inquire about further, though I doubt Gunny will have much of an answer.  Oh well.  In the end, it doesn’t matter much, but it’s still good to know.