Our lives are full of examples where a single thing can be complemented, making it even better. The simple equation where one plus one equals two no longer applies: instead it makes three.

Marriage and relationships could be the purest example of two parts coming together to enhance the whole. Equally, from dawn to dusk, there are examples that fill our day: toast and honey, meatballs and lingonberries (if you're Swedish), or a gin and tonic. All great things alone, but all better together.

It's not just food and couples, though. Rarely do we think of our sports equipment, such as helmets and sunglasses, in the same way. Every one of us, however, will have suffered when the complements are not made; where details are not tuned to perfection and mire the performance and experience.

Indeed the more you pressure your equipment and yourself, the more a weakness will show, sucking away focus from the task in hand. It might be ventilation, fit, weight, storage, or any number of details that begin to show their fault lines.

At the opposite end of the scale are pieces of equipment that work perfectly. Designed to complement each other together, they just work, no matter how hard you push them, or how long you journey beyond the horizon. There is no interference, no compromise of the experience or performance, just a seamless fit.

It's probably a healthy sign that few of us speak to our helmets and sunglasses. But if we did, the biggest compliment we could ever give them is that they just worked. That we could forget they were there, knowing they were excelling at what they were designed for, complementing themselves to compliment us.