I think my dd had both colic and was/is high needs. The sort of nightly witching hour and the screaming about gas pains is what I would refer to as colic and that tapered somewhere around 4 months. The high needs constant screaming, needing to be held all of the time changed dramatically at six months when she could sit up. At 17 months, she still gets mad about diaper changes, the carseat, and changing clothes, but it's very specific. It's nothing like having a child screaming all of the time.
I totally relate about that comment about every child being colicky. Another new mother talked to me about that at a wedding reception and I told her that my daughter screamed for 10 hours straight. The question immediately became, "Oh my god, I can't stand 20 minutes, what did you do?". I told her we went crazy.

Also, the sleep consultant I met with said that she had met only 2 or 3 other babies that had had true colic. According to Dr. Karp, I think he says only 20% of babies have colic. I wonder if high needs is like 5%?

I agree, that in some ways colic or high needs is when the baby can't be consoled with the 5 S's. Those type of techniques helped some, but most of the time they didn't. It would seem like some combination would work for a few days and then stop. Then I'd try some other combo. I felt like, if it's a science experiment, then it isn't really a solution.