For as long as you are alive you can change your brain to benefit you!
Neuroplasticity is activated when you challenge your brain by learning skills such as a new; language, games, dance or new fields of study, for example.
This causes the creation of new connections within the brain. This 'brain training' can help you stay 'younger' and free you from old or unhelpful patterns such as negativity or fear that may be an undercurrent in your life.
This is not just 'use it or lose it' but use your brain 'differently' to build more of what you want in your life.