Why is my Blog Page ID == First Post ID?

Question

It is possible that I'm doing something wrong. Currently I'm using index.php as the main blog page. I have a page setup for the Blog and set it up in my Settings. When I try to get the Blog Page ID though it always shows the first posts ID instead. I'm not running any additional queries anywhere besides the normal Loop.

Why is my code showing the Post ID versus the Page ID?

Index.php Code:

<?php get_header(); ?>

<?php get_sidebar(); ?>

<?php
    echo $post->ID;  // First Post ID
    echo get_queried_object_id(); // First Post ID
?>

<div id="content" class="blog">
<?php if(have_posts()) : ?>
                <?php while(have_posts()) : the_post(); ?>
                    <div <?php post_class('blog-entry') ?> id="post-<?php the_ID(); ?>">
                        <h1>
                            <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>">
                                <?php the_title(); ?>
                            </a>
                        </h1>
                        <small>
                            by Company <?php the_time('F jS, Y') ?> / 
                            <a href="<?php the_permalink(); ?>/#comments">Share Comment</a>
                        </small>

                        <div class="entry">
                            <?php the_excerpt(); ?>
                        </div>

                        <p class="postmetadata">
                            <span style="text-align: left; float: left;">
                                <a href="<?php the_permalink(); ?>" title="Read More">Continue Reading &raquo;</a>
                            </span>
                        </p>
                        <div class="clear"></div>
                    </div>
                <?php endwhile; ?>
                <div id="blogNav">
                    <span class="prev"><?php previous_posts_link('&laquo; Previous Page'); ?></span>
                    <span class="next"><?php next_posts_link('Next Page &raquo;'); ?></span>
                </div>
            <?php endif; ?>
</div>
<?php get_footer(); ?>

Answer 1

the 'posts page' ID when using a static front page and a different posts page is:

get_option( 'page_for_posts' )

in some context:

if( is_home() && get_option( 'page_for_posts' ) ) { 
  $page_ID = get_option( 'page_for_posts' ); 
}

Answer 2

Why don't just :

if( is_home() ) { 
  $page_ID = get_option( 'page_for_posts' ); 
}

?