Jesus likens the “coming of the Son of man” or the “days of the Son of man” to two other periods of time – the “days of Noah” or the “days that were before the flood”, and the “days of Lot”. In the days of Noah they were “eating and drinking, marrying and giving in marriage”. In the days of Lot “they drank, they bought, they sold, they planted, they builded”. In either case, the basic meaning is that life went on as normal with most people totally unaware of the catastrophes that were about to happen. This is why Jesus tells us to watch and pray, and not be overcome with the cares of this life so that we do not fall into the same trap.
But as the days of Noe [were], so shall also the coming of the Son of man be. 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, And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be. Then shall two be in the field; the one shall be taken, and the other left. Two [women shall be] grinding at the mill; the one shall be taken, and the other left. Watch therefore: for ye know not what hour your Lord doth come. But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up. Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh. (Matthew 24:37-44)
And as it was in the days of Noe, so shall it be also in the days of the Son of man. They did eat, they drank, they married wives, they were given in marriage, until the day that Noe entered into the ark, and the flood came, and destroyed them all. Likewise also as it was in the days of Lot; they did eat, they drank, they bought, they sold, they planted, they builded; But the same day that Lot went out of Sodom it rained fire and brimstone from heaven, and destroyed [them] all. Even thus shall it be in the day when the Son of man is revealed. In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back. Remember Lot’s wife. Whosoever shall seek to save his life shall lose it; and whosoever shall lose his life shall preserve it. I tell you, in that night there shall be two [men] in one bed; the one shall be taken, and the other shall be left. Two [women] shall be grinding together; the one shall be taken, and the other left. Two [men] shall be in the field; the one shall be taken, and the other left. And they answered and said unto him, Where, Lord? And he said unto them, Wheresoever the body [is], thither will the eagles be gathered together. (Luke 17:26-37)