The Gift of Knowledge is knowing God's will and plan. This Gift is to understand God and His Word; and to reveal God's will and plan.
The Gift feeds us hope and love. This Gift allows you to see things for God's perspective. This allows you to speak an understanding of a truth of the mystery of Christ.
You often experience this manifested with other Gifts like the Gift of Prophecy, Gift of Understanding, Gift of Discernment, and Gift of Administration.
Through this Gift, you are guided by the Holy Spirit in your decisions and judgments in the light of Faith.
This Gift enables you to be enlightened on what is of God than to be focused on what is of the world. It allows you to know what you should hold by Faith. It directs your life with the Divine Truth. It prevents you from being misled. It helps you to totally surrender to God.
By sharing what our Lord discloses to you, others can experience the same joy and surrender, deepen the same faith, strengthen the same relationship with our God and our Church, and be led by the same Holy Spirit.
My sheep hear my voice; I know them, and they follow me.
John 10:27
By the Gift of Knowledge, says Jesus, “my sheep hear my voice” (John 10:27) and discern both earthly and heavenly truths in their proper relation to one another. Judging all things in the light of Divine truth, we cannot only distinguish between the promptings of God and the subtle wiles of the devil, we can see and praise the manifold ways in which God is glorified in His creatures. (https://www.ncregister.com/daily-news/gift-of-knowledge-helps-to-sanctify-the-world-around-us)
Saint Anna Schäffer
She saw in dreams the death of her brother and others.
One day, a couple visited her. She told them, "I have been waiting for you all day because, yesterday, during the potato harvest, you said that today you would come to visit me, and today you did not come." The couple was amazed that she knew.
One day, she knew that 2 teachers wanted to visit her. When they entered her room, she rebuked them by name. They were surprised that St Anna knew their names even when they have never been there. St Anna told them that they want to put her through interrogation. Upon hearing this, the two went away.
Watch this video for more manifestations. (13:05 minutes)