Calling for an explanation

If I am playing a board game and the last ten rolls of my die were 1, that calls out for an explanation. If only Jewish and Ethiopian people get Tay-Sachs disease, that calls out for an explanation.

It seems right to say that

1. a fact calls out for an explanation provided it is the sort of fact that we would expect to have an explanation, a fact whose nature is such that it "should" have an explanation, a fact such that we would be disappointed in reality in not having an explanation of.

But now consider two boring facts:

2. 44877 x 5757 = 258356889
3. Bob is wearing a shirt

These are facts that we all expect to have an explanation (e.g., the explanation of (2) is long and boring, involving many instance of the distributive law and the explanation of (3) presumably has to do with psychosocial and physical facts). They are, moreover, facts that "should" have an explanation. There would be something seriously wrong with logic itself if a complex multiplication fact had no explanation (it's certainly not a candidate for being a Goedelian unprovable truth), and with reality if people wore shirts for no reason at all.

So by (1), these would have to be facts that call out for an explanation. But I don't hear their cry. I am confident that they have explanations, but I wouldn't say that they call out for them. So it doesn't seem that (1) captures the concept of calling out for an explanation.

As I reflect on cases, it seems to me that calling out for an explanation has something to do with the intellectual desirability of having an explanation rather. Someone with a healthy level of curiosity would want to know why the last ten rolls were 1 or why only Jewish and Ethiopian people get Tay-Sachs. On the other hand, while I'm confident that there is a fine mathematical reason why 44877 x 5757 = 258356889, I have no desire to know that reason, even though I have at least a healthy degree of curiosity about mathematics.

This suggests to me an anthropocentric (and degreed) story like the following:

4. A fact calls out for an explanation to the degree that one would be intellectually unfulfilled in not knowing an explanation.

It is sometimes said that a fact's calling out for an explanation is evidence that it has an explanation. I think (4) coheres with this. That something is needed for our fulfillment is evidence that the thing is possible. For beings tend to be capable of fulfillment. (This is a kind of cosmic optimism. No doubt connected to theism, but in what direction the connection runs needs investigation.)