No. No. No.
This ruins a child.
Children are one of the most precious aspects of life, and yet they often are mistreated and abused. If you are a parent, your most important task is to raise your child with as little trauma as possible. Firmness, consistency, and patience are essential. There will undoubtedly be times when you have to correct a child to prevent mistakes and bad habits. However, when it comes to a child’s curiosity, individuality, or initiative, there should never be any discouragement. In that sense, it is wrong to say no.
There is a legend about a thief who stole into heaven and took the peaches that gave immortality. He returned to earth and was about to eat them when he chanced upon two little boys. Taken with their intelligence, he asked them riddle after riddle about the deepest meanings of life and they answered with laughing ease. The thief decided to share his peaches with the boys, and they all became immortal.
If the boys had had their curiosity killed early in life, could they have answered well? If a thief could be kind to children, can’t the rest of us be too? And if the children never had an opportunity, could they have become immortals?