Common sense is usually connected to universal truths. If you do not have regular social interaction, you might not learn what constitutes common sense and how to use it. This is why very smart people with high IQs tend to ignore common sense might lack it.

Common sense is a sound, practical judgment that's usually developed through life experience rather than any kind of formal training. Developing common sense can seem like a difficult thing, but you can easily practice using common sense by being more aware and reflecting on situations before you make decisions. As you develop more common sense, you’ll be able to make smarter choices.

Common sense is a natural ability to make appropriate judgments about practical matters. You do not need to have specialized knowledge to exercise common sense and make a sound judgment in everyday life situations. It is common sense not to jump into the deep water when you do not know how to swim. The do's and don'ts in any particular situations that enrich the common sense of a person are a byproduct of life-experiences.