There is a saying that Ignorant is bliss. Sometimes no knowing might not be a bad thing, as not knowing implies lesser expectations, hence lesser pain or disappointment. But ignorance is not always a good thing.
Being ignorant means that one is not only lack of knowledge but also lack the awareness. What is bad about ignorance is the lack of awareness. One can be lacking of the awareness of themselves, while sometimes thinking highly of themselves. This causes one's downfall and also sufferings and unhappiness. The lack of awareness can also mean that one is not in tune with the situation around them. This often led to one making a wrong decision or remark that will come back to haunt them.
Hence, ignorant is not really a bliss, but can contribute to many sufferings, unhappiness and misaligned expectations. Therefore, we have to be more aware of not only ourselves, but also our surroundings. This is where mindfulness practise can help. Keep up your mindfulness practise!