All of us go through changes throughout life, nobody can stay the same forever, nor should they. Personally, I agree with this quote because if I were to allow my past to take away from who I am as a person, life would be pointless. It would be based on a matter of circumstance and luck and you’d essentially be going with the motions, come what may, and letting everything affect you (positive or negative). Instead, this energy is better utilized by learning & improving upon yourself over time. Growing up is a part of the process.