how can you say that Gulliver is an adventurous person

He is adventurous because he travels to many different lands and wants to learn about their cultures, customs, and different ways in which they live.

Gulliver longs to explore the seas. After Puritan College he became an apprentice to a surgeon in London, during which time he also learned about navigation and mathematics in preparation for a future on the sea, "as I always believed it would be some time or other my fortune to do." Next he studied "Physick" (medicine) because he thought it would be "useful in long Voyages.