I'm not who you asked, but here are what good generalizations are to me:

1) days contain more photons than nights

2) water boils at 100 degrees Celsius

3) eating excessive sugar will lead to obesity

They seem like good generalizations because they are true most of the time from the perspective of the speaker and listener, even thought there may be some exceptions, they are materially more rare:

1) except in multi-solar systems, where this can get complicated

2) except when under pressures different than approximately sea level atmosphere

3) except when ___ I'm not sure but I bet there is some medical exception, maybe excessive exercise?

Bad generalizations will have many many exceptions such that the generalizations is materially lossy and even dangerous (e.g. "everything in moderation" -> murder in moderation, meth in moderation, punching grandmas in the face in moderation, etc.)