Psychologists believe that fear is caused by ignorance of the things you will be in contact with, that is to say, you do n’t have the bottom of your heart, so you will be afraid. So, what does adventure mean? Adventure is "knowing that there are tigers in the mountains, and they tend to go to the mountains. ". this means? ['The adventurous person has a bottom in mind.', 'The adventurous overcomes fear to some extent.', 'The adventurous person only has "paper tigers".', 'The adventurous person has the ability to fight tigers.']