What difficulty does a person with insomnia typically face?

A person with insomnia typically faces difficulty falling and staying asleep at night, which is accurately represented by the chosen response. Insomnia is characterized by the ongoing struggle to initiate sleep, the inability to maintain sleep throughout the night, or waking up too early and not being able to return to sleep. This condition can lead to feelings of fatigue, irritability, and cognitive impairments during the day due to the lack of restorative sleep.

When considering the other options, sleeping excessively during the day would suggest a different sleep disorder, such as hypersomnia, and is not a symptom of insomnia. Dreaming vividly can occur in various individuals regardless of sleep disorders and is not specifically related to insomnia. While experiencing nightmares can affect sleep quality, it is not a defining characteristic of insomnia itself, and not everyone with insomnia experiences this symptom. Therefore, the primary issue associated with insomnia is indeed the challenge of falling and remaining asleep at night.