Yes, you are wrong—although I suspect many people have the same idea about heaven that you do. After all, what could be more boring than simply sitting around all day doing nothing?
But we won't be doing nothing! For one thing, the Bible makes it clear that God will have work for us to do. The Bible says of heaven, "The throne of God and of the Lamb (Christ) will be in the city, and his servants will serve him" (Revelation 22:3). The Bible doesn't tell us in detail what this means—but unlike our lives right now, we will never grow tired or weary in heaven as we do God's work.
Think too of all the new things God will show us when we get to heaven! Distant galaxies that are only a faint speck in an astronomer's telescope today will be ours to explore—and we will have all eternity to do it. Think of it!
Most of all, we will have all eternity to experience the depth of God's greatness and love. The Bible says, "What we will be has not yet been made known. But we know that when he appears, we shall be like him, for we shall see him as he is" (1 John 3:2). Is this your hope? Don't let another day go by without Christ, but open your heart to Him today—and encourage your nephew to do so too. It is the most important decision you will ever make.