I don't know how, what, why, etc.
informal› used to add force to criticisms, expressions of surprise, etc.:
I don't know why you bother.
(I don't know how, what, why, etc.在剑桥高级学习词典和同义词词典的解释 ©剑桥大学出版社)
“每日一词”
likeable
A likeable person is pleasant and easy to like.