The assistant I once supervised has left. It's my first time as a manager, and I didn't handle it well. I've done my best to do what I should. The most frequent advice I gave was: don't waste time. Now, in the future, and always: don't waste time. Teacher Zhang Xuefeng's passing reminds me that in my limited lifetime, I shouldn't do things that will make me regret. Work and learning bring me joy.