It's important to remember that children at the age of three are still developing and learning about the world around them. It is not fair to label your child as "stupid" based on their reactions or understanding at this young age. Children may have a limited understanding of cause and effect, leading to misunderstandings or misconceptions.
In the case of your son's reaction to the microwave heating his lunch, it's possible that he may not fully grasp the concept of how microwaves work or the heating process. He might see the food disappear inside the microwave and not understand that it's still there and being heated.
As a parent or caregiver, it's essential to be patient and understanding during these moments of confusion or distress. Instead of using negative labels, try to explain things in a simple and clear manner that matches your child's developmental level. You can show him that the food is still there after heating, and use this opportunity to teach him about microwaves and how they work.
Remember, every child learns at their own pace, and it's essential to provide a supportive and nurturing environment to help them grow and understand the world around them. Positive reinforcement and gentle guidance will go a long way in fostering their cognitive and emotional development.