TITLE: Intuitive functional analysis book
QUESTION [5 upvotes]: I want to know functional analysis book like Terence tao's real analysis and measure theory book, full of intuition. I am aware of linear algebra, real analysis, measure theory, Probability theory.

REPLY [6 votes]: The book  A. Ya.  Helemskii, Lectures and exercises on functional analysis. AMS, Providence, RI, 2006 (translation from the Russian original) is IMHO well written and quite intuitive (check e.g. the MathSciNet review which is quite glowing).