An enormous attachment to anything is certain to hurt you one day.

The wise choose to accept and adapt instead of being too attached.

Attachment is the reason for resisting change often, irrespective of who you are. 
I recall being too reluctant to change my school or my profession, as I was not daring to jump into the new environment. In my assessment, nothing was wrong with being attached to known surroundings. To me, it was not excessive longing. 
In the middle of my professional career, I once chose to go to different places, and then I realized the taste of detachment. Every time there is a new place, a new team, new customers, and new learning and testing, my ability to adapt. 
Being attached to your place of birth, parents, teachers, friends, profession, material gains, relations, hobbies, food habits, attire, and values is ingrained in your thinking and behaviour. They are the tools of attachment. I was inclined to be tagged with my languages and known faces, and I felt no need to upgrade to a new version in the 20s or 30s. 
People are attached to place, profession, position, and presumptions up to a limit, and they get their purpose of living served to their advantage. Smoothness is intact when attachment is not too strong. 
Know that strong attachments kill the talent to grow, as I have witnessed in numerous instances. 
So all sorts of attachments need to be handled carefully. 
Attachment is a feeling that connects you to people, places, assets, or causes. 
It is learned that your mental frame is full of stuff before the age of 14 or so. The attachment is nurtured during this time, and therefore you feel heavy if you are forced to live in different settings at any stage. 
In cases of extreme attachment, it creates a jerk when we are separated in any way and causes hurt that can’t be described in words. 
It is said that you can’t enjoy the beauty of things until you navigate to unknown territories. All such separations are meant to elevate you, but you feel pain at that point. 
At times, things happen that were never thought of. Loss is unbearable, but there is no remedy in sight. 
A simple example in the present scenario is job loss. It hurts. It hurts deeply. Some go for other jobs, some change tracks, and some just assume other doors are closed. Some have resilience, and many get confused. 
Growth happens only when we embrace change. It is a universal law.
Sometimes we are pushed forward and then get stagnant, and changes happen in between. We play with happenings that are both desirable and undesirable. 
Attachment with known places, known figures, expertise, and trust up to a limit is okay. After that, the status quo is detrimental to the growth trajectory. 
Nothing on this globe remains the same in the long run, though things remain interconnected in a new order too. We feel isolated until we get accustomed to new situations, setups, and responsibilities. 
I am not with the people I played with during school. I am not at home; I was born. I am not serving the people whom I was supposed to support. It is the effect of change; some were planned (the big picture), and more just happened (efforts).
We are too attached to our offspring. We get detached over time. We were very close to siblings under one roof. They are now scattered in different locations. Nothing is surprising.
When we are ready to accept all these detachments, matter passes on without any hurt. Matters worsen when we classify changes as non-acceptable.
Some detachment is too heavy to bear. But we have no control. We may pacify ourselves by saying that sometimes fire is required for the benefit of forests. We must say yes to situations when they are in flow or where our future selves are likely to be. 
 
Summary
 
Too much attachment is going to hurt you. Keep attachments up to the level of necessity, not extreme. 
Attachment changes, and we need to keep it flowing, not getting fixed.