Interesting and something to think about.
Could this be illustrating how swiftly and unexpectedly for some the end will come?
I mean if you read the verses directly before those, that seems to be what it is explaining...IMHO
36 But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only.
37 But as the days of Noah were, so shall also the coming of the Son of man be.
38 For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark,
39 And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be.
40 Then shall two be in the field; the one shall be taken, and the other left.
Then directly before that it is talking about the complete end of time.