Well, when he wakes up, he could find that his loved ones are all gone and struggle to fit into this new era. Maybe he'll have a hard time adapting to all the advancements and changes.
He could face a lot of challenges. For example, he might not understand the new language or culture. Also, he might have trouble finding his place in a society that has moved on without him.
He might wake up to a completely different world. Technology, society, and everything could have changed beyond recognition.