Stress, mental/emotional stress. When my biologist kid was talking about how harmful stress is, I was just thinking it's normal, right? Like how the fuck am I supposed to avoid stress? No person could, we have to be made to handle it, or even benefit from it? Like how stressing my muscles makes them healthier?

No. Early life stress, damaging. Midlife stress, damaging. Old age stress, damaging. Mental stress causes physical damage.