User talk:2600:6C5D:5A00:7E0:45E2:7BB1:C784:6BEE

Three points:

1. This paragraph is confusing:

"The first climacteric occurs in the seventh year of a person's life; the rest are multiples of the first, such as 21, 49, 56, and 63. The grand climacteric usually refers to the 63rd year, with the dangers here being supposedly more imminent;[2] but may refer to the 49th (7 × 7) or the 81st (9 × 9).."

81 does not have the factor 7. So either this is an error, or it should be made clear that climacteric years need not be multiples of 7.

2. The number 7 was used to symbolize completion or perfection across much of the ancient world. There is no reason to suppose Pythagorus originated this custom. As we know, the advent of agriculture promoted stargazing, which in turn promoted various stargazing theories among the ancients. There are, in the pre-telescope era, seven heavenly bodies and that fact is doubtless the origin of belief that "7" represents completion.

3. One can understand how the Greek thinkers (and not only Greek) might have come up with the idea that if "7" represents completion in heaven, then it should do so on earth, particularly with regard to cycles in a human life. We, from the vantage point of modern statistical methods, can see that the idea that danger lurks larger in certain years is a result of "connecting dots" in a way that is only subjectively correct. That is, the mortality rate was extremely high among humans until modern medicine flattened the curve, causing people to believe all sorts of nonsense as to why humans die. Even today, when death is on the rise -- as in the current Covid epidemic -- there is a tendency to see "causes" and associations that are in part or as a whole illusionary.