We had fraternal twin girls. One would sleep soundly and the other spent the first six months of her life with colic and never made it through a single night without waking up loudly crying. At the recommendation of our pediatrician we took her twice to a specialist who did cranial massage and realigned the plates of her skull. After the first visit she slept soundly for two weeks. Then the crying started again. Second visit ... never a problem again. Every baby, like fingerprints and every person, is completely unique.
Cranial Massage! I didn’t know this was a commonly used method. You had a good doctor. Someone open to holistic, noninvasive disciplines that have likely been used for centuries.