It's OK to be wrong. It's disastrous to stay wrong

It is perfectly fine to change your opinion. You may be wrong or facts may have changed. Here's the tale of one of the smartest people - Warren Buffett and airlines.

Buffett in 2007 when  asked about airlines:

In 2016 he started buying airlines:

In 2020 he started selling his shares at a loss after the Covid-19 crisis:

Buffett’s Berkshire Sells Airline Stocks Amid Crisis
Warren Buffett’s Berkshire Hathaway Sells Millions of Shares of Delta and Southwest as coronavirus crisis paralyzes airlines.