This quote is a beautiful metaphor that encapsulates the journey of youth. "The tempests of youth" refer to the turbulent times, the struggles, the challenges, and the uncertainties that young people often face. These could be related to self-discovery, societal pressures, academic stress, or emotional upheavals. The "tempests" are a necessary part of growth and maturity, and they shape us into who we become.

On the other hand, "days of brilliant sunshine" symbolize the moments of joy, success, and clarity. These are the times when everything seems to fall into place, when we feel invincible, loved, and full of potential. These moments, too, are integral to the youth experience, as they provide balance, hope, and motivation.

In essence, the quote suggests that youth is a blend of highs and lows, of storms and sunshine. Both are necessary, both are valuable, and both contribute to the richness and diversity of the human experience.

Applying this idea to today’s world or personal development, we can understand that life will always be a mix of good and bad times. Especially in today’s fast-paced, highly competitive, and often stressful environment, young people may face numerous "tempests." However, these challenges should not be feared or avoided. Instead, they should be embraced as opportunities for growth, learning, and self-improvement.

Similarly, the "days of brilliant sunshine" should be cherished and appreciated. They serve as reminders of our capabilities, of the beauty of life, and of the potential for happiness and success. They provide the motivation to keep going, to keep growing, and to keep striving.

So, irrespective of the stage of life we’re in, it’s crucial to remember that both the tempests and the sunshine are part of the journey. They shape us, teach us, and ultimately, make us who we are.