This reminds me of when I coach a kid in chess and the first thing I ask them is what they want to achieve. A fairly common response is to not lose. At first that doesn't sound unreasonable, yet the goal there doesn't require any coaching at all - simply only play terrible players!
So too with knowledge. The path to never believing anything false would be to simply minimize the amount you learn, and certainly to avoid learning anything developed within the past century or so. It's not a great perspective for self betterment. Learning from one's mistakes is the path to improvement in most of every domain. Mistakes and falsehoods are nothing to regret. If anything, they're something to rejoice over. It's only the fool that believes all he thinks must be true.