I worked with a swim coach back in my 30s when I used to compete in triathlons. During our first lesson, he told me that we would focus on one or two things, and only when I’d mastered those changes would we move on to the next area of focus. He said focusing on more than one or two techniques at a time wouldn’t lead to progress.

What’s true of swimming drills is also true in life: Our brains can’t handle tackling more than two changes at a time. Scientifically, this is known as the “Resilience Rule of 2.”

In her book, The 5 Resets, which teaches people how to better deal with stress, Harvard-trained physician Dr. Aditi Nerurkar discusses the Resilience Rule of 2. She says, “Change is a stressor for your brain. Even positive changes in your life can be a stress.” Trying to make more than two changes at a time is too stressful, causes you to feel overwhelmed, and often leads to you doing nothing.

So, if you want to implement changes in your life, just pick one or two things to focus on. Like with swimming drills, stick at those things until you’ve mastered them, or they become habits. The key is to focus on incremental changes that will build with time. By mastering one or two changes, you’ll feel a sense of accomplishment and be motivated to continue your journey of positive change.

For example, if your goal is to eat healthier to lose weight, just pick one or two things, like drinking a full glass of water before starting each meal and eating at least two apples a day. That may not seem like much, but after these things become a habit, you can move on to the next two eating goals.