In Jeremiah 29:10 the prophet is telling them that the captivity in Babylon will last for 70 years. Later in the chapter the people reject that message as well, opting instead to believe those who tell them that it is not going to be that bad.
In Jeremiah 29 – 33, God is telling the people that He is going to fix it. He outlines for them a new covenant. A covenant where God will enable their obedience. That covenant has its fulfillment in the life, death, resurrection, ascension, and rule of His Son.
So we are familiar with the passage, but not so much the context. But, it is much easier to put the one verse on the pillow, the greeting card, or bumper sticker.