I can understand why such a situation could evoke different emotions in a person.
How someone would react to their grandparent scratching initials on something they bought for them would depend on various factors, including the individual's personality, their relationship with their grandparent, and the context of the situation. Some people might feel upset or disappointed because the item they needed for school now has markings on it. Others might be more understanding and see it as a well-intentioned gesture from their grandparent.
It's essential to remember that everyone's feelings and reactions are valid. If you find yourself feeling upset about the situation, it's okay to acknowledge those emotions. It may be helpful to talk to your grandparent and express how you feel calmly and respectfully. Communication can often lead to a better understanding of each other's perspectives and can potentially resolve any issues that arise.
In some cases, the intentions behind the actions matter. If your grandparent did it out of love and thought it was a way of personalizing the item for you, they might not have realized it would upset you. Talking to them about how it made you feel can help prevent similar situations in the future.
Ultimately, the way you feel about the situation is entirely valid, and how you choose to address it will depend on your own comfort level and relationship with your grandparent.