When Knowing Isn’t Enough: What Is Capacity?

Last week, we explored the small space between reaction and intention; you can read that here. It is that brief moment when we can pause, notice what is happening, and choose how we want to respond. After reflecting on that article, I was left with another question.

Why does that space feel so different from one day to the next?

Some days, we can pause, stay curious, and respond in a way that feels true to the person, parent, friend, or leader we want to be. Other days, however, that same pause seems to disappear, and we react before we even realize it. Sometimes, even later, we sit with guilt, shame, or confusion, wondering, “If I knew better, why couldn’t I do better in this moment?”

Many of us have come to believe that if we struggle in those moments, the answer must be more patience, self-control, or willpower. I don’t think the answer is more willpower, and I don’t think that’s the whole story. I think we’ve been asking the wrong question.

Capacity.

Capacity is a word we hear often, but do we actually know what it means? Or have we been given only part of the picture? Today, I’d like us to explore that together.

The more I have studied human development, trauma, attachment, and everyday life, the more I have come to believe that capacity isn’t one thing with one simple definition. It is the result of many parts of our lives working together. Understanding those pieces changes not only how we see ourselves but also how we see our children and the people around us.

Capacity isn’t something we fill once and keep forever. It isn’t something we fix. It develops throughout life and continues to grow and fluctuate as we move through it.

So, what is capacity?

When I talk about capacity, I am not referring to intelligence, character, or knowledge. Instead, I mean our ability to access the physical, emotional, cognitive, and relational resources we need in the moment.

Most of us already carry far more knowledge, skills, and experience than we are able to access in every moment. The challenge isn’t simply learning more. It’s being able to access what we already know when life becomes overwhelming.

Imagine having the tools you need locked inside a toolbox. The tools haven’t disappeared. You still own them. But if you cannot open the toolbox when you need it most, having those tools doesn’t change what happens in that moment.

Capacity is what allows us to open the toolbox when we need it most.

When our capacity is available, we can access what we know. We are better able to think clearly, stay curious, solve problems, regulate our emotions, and respond in ways that reflect the person we want to be. We have the self-awareness to notice what is happening within us before our reactions take over.

When our capacity is limited, our attention shifts from understanding what is happening to making it stop. We become focused on ending the crying, the arguing, the behaviour, or even our own uncomfortable feelings so our nervous system can find relief. In those moments, our thinking narrows, our emotions grow louder, and we become more likely to react from old patterns, habits, and survival strategies than from the person or parent we are trying to become.

Our knowledge is still there, but it becomes much harder to access. The more dysregulated our nervous system becomes, the harder it is to access what was learned when we were calm. That isn’t an excuse, but it is an explanation. Explanations create opportunities for change.

Understanding this doesn’t remove responsibility, but it does remove shame. Shame rarely helps us grow. There is an important difference between saying, “I didn’t know better,” and saying, “I couldn’t access what I knew.” One invites judgment. The other invites curiosity. Curiosity opens the door to growth.

So, where does capacity come from?

We are not born with it. Babies are not born able to calm themselves. Every one of us arrived in the world relying on someone else’s capacity before we could develop our own. Babies borrow the calm of the people caring for them. Through thousands of ordinary moments of being comforted, soothed, understood, and helped through difficult feelings, children slowly begin to build the ability to do those things for themselves.

As children, we don’t simply learn from what our parents say. We learn from how they move through the world. Children are incredible observers and imitators. They watch how the adults around them respond to stress, conflict, disappointment, joy, and connection. When caregivers have the capacity to regulate, repair, and return after difficult moments, children gradually develop those same abilities. When caregivers are overwhelmed by chronic stress, trauma, mental health challenges, poverty, addiction, or hardships of their own, children adapt to those environments too.

This isn’t about blame. It is about understanding. None of us chose the capacity we started with, just as none of us chose the environments that first shaped it. Much of our starting capacity was shaped long before we had any say in it.

The encouraging part is that capacity isn’t fixed. It develops through repeated experiences, which means it can continue to grow. We don’t become perfect, and we don’t stop having hard days. Instead, we gradually gain access to more of ourselves when life asks the most of us.

We notice sooner. We return faster. We repair more often. Little by little, the bridge between reaction and intention becomes wider.

That growth doesn’t happen overnight. It happens one moment, one relationship, and one experience at a time.

So, if you have ever found yourself asking, “If I know better, why didn’t I do better?” I hope you leave this article with a different question.

What was available to me in that moment?

Because that question doesn’t lead us toward shame. It leads us toward understanding. And understanding is where growth begins.

Next week, I want to introduce you to a mother whose story illustrates this perfectly. She loves her children deeply. She knows the kind of parent she wants to be. Yet, on one ordinary morning, she responds to two very similar moments in two completely different ways.

The difference isn’t how much she loves her children. It isn’t how much she knows about parenting. It isn’t her motivation to do better.

It’s capacity.