Arjuna compares the mind to the wind and wants to know as to how to control it, so that it maintains balance. Krishna says that it's certainly difficult, but it can be achieved through the practice of Vairagya .
The mind is evolved to judge inputs brought in by the senses into safe and unsafe and uses memory while doing so. This ability helped us survive and prosper during evolution.
The same ability of the mind can be used for internal judging, which is called awareness. We can feed our own thoughts and feelings back to the judging mind to improve the quality of judging. Similar feedback mechanisms are used to enhance machine learning as well as to stabilize electronic systems. Lord Krishna is hinting at developing this faculty through practice as this doesn't come naturally. In terms of neuroscience, it's like building new neural networks.
It's easier to understand Vairagya by understanding its polar opposite Raag . Raag is broadly a chase for pleasures in the manifested world like physical beauty, careers and material possessions. As per the principle of polarity, every raag ends in vairagya but our attention is always on raag and we tend to overlook vairaagya .
Some philosophies like Stoicism advocate the use of death, which is the peak of Vairagya . It's called 'Memento Mori', i.e. constantly revisiting death. In this they keep something(memento) as a reminder of death at a prominent location in the work place or at home so that they constantly revisit it. Indian philosophy refers to this as Shamshan Vairagya .
Krishna says that if you put Vairagya into practice, it will stabilize the mind at the centre.
These lockdown periods gave us glimpses of vairagya moments. A small steak of vairagya generated can help us to attain a balanced mind for peace and joy.
Source - Daily World