Last year, one of my coworkers told me about “spring depression”, apparently a common condition in Japan. At the time, I was confused and told him about SAD (seasonal affective disorder), which happens in the winter, and asked if that’s what he meant. No, he replied, it’s spring that is dangerous, because the power of nature is so strong, it overpowers you.
I understand now. It’s the feeling of helplessness in the face of renewal. Life is moving forward, but you are still and there is nothing you can do about it.