"「自分のものは頭の中の数立方センチメートルだけだった。」"

Simplified Meaning:

This quote means that the only thing you truly have control over is your own mind and thoughts. It suggests that everything else in life—like our belongings, surroundings, or even our bodies—can be taken away or influenced by others. For example, think about how other people can always give opinions about what we do or even try to change our actions. However, no one can directly change what we think or believe unless we allow them to. Imagine a writer in prison. They might lose their freedom to move or live comfortably, but no one can stop their imagination or control their inner thoughts. The quote reminds us that our thoughts are our most private and secure possessions. We can apply this by focusing on keeping our minds strong and healthy, even when situations outside our control are challenging. It encourages us to find peace and strength inside ourselves, knowing that our thoughts and how we react to events are always up to us.