As we grow older, we often become more selective about who we allow within our inner circle.Social pruning. Friendships can wax and wane.Science points to a host of qualities that are integral to keeping lasting friendships alive, such as proximity, shared memories, and even similar brainwaves. On the flip side, researchers also argue that failure to adapt to the current state of a friendship can threaten its longevity.As we get older, our lives naturally get busier and more complicated. And while many friendships stall or even fracture at this juncture, the strongest ones are flexible enough to survive these choppy waters. Being a lifelong friend extends beyond the traits we like to place on a pedestal – loyalty, kindness, or a similar sense of humour. Instead, it’s about adaptation and understanding that your expectations and approach within your friendship might need to change during certain phases. Demonstrating compassion and flexibility during challenging times can make a big difference in making (and keeping) lifelong friends.A low-maintenance friend should not be mistaken for someone who’s not committed. Rather, they don’t expect the friendship you share to conform to a given set of conditions. The bond you share doesn’t have to look a certain way – or equate to time spent together – in order to be considered genuine.In fact, low-maintenance friendships are some of the most valuable relationships you can have. This is because while you don’t speak to one another every day, they are there when you need them.The older you get, the less patience you’ll have for being put through the wringer. Low-maintenance friends invest time and effort at a slow and steady pace, providing an uncomplicated presence. To them, friendship is a continuum; a place where closeness is assumed, no matter what happens in between. They’re flexible enough to stand by when life gets in the way and, most importantly, fall back in where it counts.