The Buddha says, when you’re asked about action, you don’t talk just in terms of stress. You talk about the three kinds of actions: actions that lead to pleasure, that lead to pain, and actions that lead to neither pleasure nor pain.

"We develop skillful qualities in the mind. Yet sometimes the teachings on inconstancy [anicca] seem to undermine the developing side. You think about developing something in the mind, and something inside you says, “Well, it’s going to be inconstant anyhow. No matter what you do, the results will be inconstant, so why bother?” That’s a wrong use of the teaching.

It’s like that time when the young monk was asked, “What are the results of action?” and he said, “Stress. Pain.” The person asking him, a wanderer from another sect, said “I’ve never heard Buddhist monks talk that way. You’d better go check with the Buddha.” So he does, via Ānanda. And the Buddha says, when you’re asked about action, you don’t talk just in terms of stress. You talk about the three kinds of actions: actions that lead to pleasure, that lead to pain, and actions that lead to neither pleasure nor pain. A nearby monk happened to overhear this, and said, “Well, maybe young monk was thinking about the principle that all feelings are stressful.” The Buddha said, “This is not the time to use that teaching.”

In the same way, the teaching on inconstancy is not for use when you’re trying to develop good qualities in the mind. You have to think about what can be accomplished so that you can put forth the right effort. After all, the Buddha used the principle of change in his own life to achieve awakening. So, a willingness to use things that change is not doomed to failure."

~ Thanissaro Bhikkhu "Undefeatism"