Genesis 42:18-21 (NIV):
On the third day, Joseph said to them, “Do this and you will live, for I fear God: If you are honest men, let one of your brothers stay here in prison, while the rest of you go and take grain back for your starving households. But you must bring your youngest brother to me, so that your words may be verified and that you may not die.” This they proceeded to do.
They said to one another, “Surely we are being punished because of our brother. We saw how distressed he was when he pleaded with us for his life, but we would not listen; that’s why this distress has come on us.”
Why did they immediately jump to that conclusion? Was it because they saw Joseph and he reminded them of his younger self (so they were thinking about it anyway), or did they just feel guilty "in general"?