Galileo challenged Aristotle's teaching

In 1589 Galileo challenged Aristotle's teaching. He invited learned
professors to the base of the Leaning Tower of Pisa. Galileo went to the top of the tower and at exactly the same moment pushed off a ten-pound and a one-pound weight.

Both landed at the same instant, but the professors still wouldn't believe what they saw. They insisted Aristotle was right.

To move ahead in life and to grow—intellectually, emotionally and spiritually—it is important that we examine all our beliefs, test
them, hold to the true and discard the false. Admittedly, this is
much easier said than done but done it must be if we are to keep
learning and growing. Unless we are open to and willing to change, we get stuck in our ways and cease to grow.

We don't read much about Apollos in the Bible but he was a
contemporary of the Apostle Paul. He was a very gifted and educated man "with a thorough knowledge of the Scriptures." But he only knew about John the Baptist's baptism. So when Priscilla and Aquila heard him speak, they explained the gospel message to him more completely.

The end result was that Apollos was willing to listen, was teachable, made the necessary changes in his beliefs and as a result became a "great help" to the church.