Your brother met someone, was immediately concerned about why he was crying, and it stuck with him weeks after never seeing him again.

That’s a wonderful display of empathy, not just some childish complaint. When we talk about how boys and socialized differently from girls, this is it. How we respond to kid’s feelings is how they perceive their own emotions. And if we cue that it is something they ought to grow out of, they will grow out of it.