Can You Learn Sign Language Just by Memorizing the Signs in a Book?

Well , Yes and No.
Yes …. you can learn but you won't be able to know it all because you won't be able to sign smooth like me because I am Deaf and ASL is my first language.
No… you will never understand Deaf people's grammar because they are far different than English grammar.
If your heart tell you that you can do it then your heart is wrong.