"Whoever loves discipline loves knowledge, but he who hates reproof is stupid"
How much do you love to learn new ways to improve? How much correction can you stand? Do you really want to get better at your job, parenting, marriage, and living for God? Then you must be willing to be corrected so you can make progress in those areas.
It is not possible to make progress without change and realizing that there is a better way.
There are an awful lot of people who want better marriages, families, careers, and connections with God. They just don't want to change anything. If they are willing to change something, they are willing to add something. But they are often unwilling to eliminate anything. We act as though maybe we aren't doing something we should but never that we are right now doing something we shouldn't.
This proverb says that whoever really loves knowledge also loves correction, rebuke, chastisement, and instruction in the proper way. It is the willingness to be corrected that tests our real love of knowledge.
whoever loves discipline loves knowledge
The Hebrew word translated discipline here in the NASB is the word musawr which means "instruction, correction, chastisement, rebuke." In this context it seems to carry with it the idea of contrary information because of the parallel idea given in the second half of the proverb: but he who hates reproof is stupid.
In other words, the person who really wants to display that they are interested in knowledge and not just getting their own way will be open to contrary knowledge -knowledge that is a rebuke to the way that you have been living; knowledge that means you must change.
Think of instruction as feedback. All of us use and enjoy feedback. When we drive and turn the steering wheel, we need the feedback of where the car actually goes to give us feedback and what to do with the steering wheel next. When we are trying to convince someone of something or sell them something, we need the feedback of what they are thinking about what we are saying. Without the feedback, we will keep doing what we think is right even though it gets no results. There are all kinds of feedback experiments where people have been hooked up to monitors and they get to see how their stomach responds to particular stresses and thoughts. People have learned how to overcome their fears and the like.