Yes, it is absolutely possible to love someone else after a significant person in your life has left, despite how difficult it may seem at the time. The phrase "the one" is often used to denote a significant romantic partner, typically one whom you have loved deeply. When this person leaves your life, it can be very painful, and it's normal to feel like you may never love again.
However, it's crucial to understand that love is not limited. People are capable of deep, profound love for many individuals throughout their lives. Each love can be unique and special in its own way. Just because you have loved someone deeply before does not mean you are incapable of experiencing the same depth of emotion for someone else.
The process can take time, and it's important to allow yourself to grieve and heal after a significant loss. Once you have healed, you may find yourself open to the possibility of new love. Remember, love isn't a matter of finding "the one" person who is perfect for you. Instead, it's about finding a person who, despite their imperfections, you choose to love and be with.