Your window of tolerance will tell you everything you need to know about your emotional world. The bigger your window, the more you'll be able to cope with life's ups and downs. That's not to say you'll never be hurt or experience trauma, but with the right social support and your resilience, you'll probably bounce back quicker than someone with a smaller window of tolerance.
Our tolerance for what are called positive and negative emotions, has everything to do with how we grew up. If we had secure attachment, that is, if we felt loved for who we were and our needs were mostly met, we'll have quite a large window of tolerance. We won't be overwhelmed or shutdown easily. That's because our parents, or whoever our primary caregiver was, would have soothed us, been there for us and our needs, and from that, we learn resilience and safety. We learn that we're fundamentally ok. We have the time and the resources to concentrate on our growth and development because we're not fighting (fleeing or freezing) for our very survival like so many children who experience repetitive abuse, whether emotional, physical and sexual.
Of course, we can learn how to expand our window of tolerance through different methods, tools and techniques, but it's always easier when we start with being and feeling loved. I liken it to a child either being on the top of a mountain, ready to fly off into their lives, or a child trudging up the mountain with a huge weight on their backs and sometimes stumbling and falling back down. With the right help, we can all be on top of the mountain which gives us a view of the bigger picture of our lives.