I'd agree as a general thing, but not for everyone.
However I'd like to see the background research to the claim that even a single time getting burnt increases the risk of cancer by quite a large factor.
Because I would suspect very few people could conclusively say they had only ever burnt once.
I mean, I tan easily. I tan slowly in light cloud, and quickly in bright sunshine. I have occasionally burned, I think. Other than the tops of my feet, which have burnt a few times, I cannot honestly tell you for definites that I have burnt anywhere, let alone more than once.
Yet, I know I have because I can remember the pricky itchy feeling...
I can say I rarely burn, but not how often. It might have only been once. It might have been 10 times. I couldn't state this accurately enough for proper research.
I would also suspect very few people currently have only burnt once. My dsis burns in light cloud, I could be mean and say even in heavy cloud and she'd probably not deny it. She used to turn bright red most years at least a couple of times. To her disgust, it would peel off leaving her as pale underneath as before.
I suspect most people who burn, have burnt multiple times.
They might say to the doctor: "Oh yes, I had a really bad burn there once" but that doesn't mean they haven't burnt their before.
I'd just be interested, because I've heard it stated several times, but never seen who did the research.