Creating static page / blog page hybrids on front-page and category-pages

Hi there everyone. I am trying to do something I think is slightly unusual; it must be possible but I just can’t figure out how to do it.

On the index page, I want to show a list of recent blog entries as per usual, with one important difference:

I want the very first blog entry to be static, i.e. always the same… And I want it to be the same format as all the other blog entries, namely with a “read more” cutoff etc.

This is so that the index page can have a “WHAT IS THIS WEBSITE ABOUT” post right at the top for new readers, as well as the more normal “new post list” underneath it.

What I have already tried:
I have tried to do another “the loop” in the template file, with a “if the_ID() == 5 {” to try and force only this one to display the first time round, then having another loop afterwards, but I don’t understand enough about how the backend works.

Any help would be GREATLY appreciated, then I want to apply a similar thing to each category, so that there is an intro post as well as regular posts, and I don’t have to go creating static pages, but every entry can use the typical “post” structure.. It seems a more congruent way to have intros to category type pages, etc.

Hope this makes sense, your comments are appreciated.

Richard