At the bottom of most blog posts here, you'll see a few tags. These are a way of categorizing entries for later viewing. I ran a test of 'Canada Day' mainly because I included 13 photos in yesterday's post and wanted to see prior years.
My blog goes back to 2003, so I've been active with this project for nineteen years! However, I have a cache of photos that no longer are on my personal web server. As a consequence, many posts from 2005 to 2009 are missing photos.
These images are not really gone, but I have to edit each entry to put them back into place. It's extremely time-consuming to edit each entry one by one. I sometimes enjoy busy work though. I think that stems from the large amounts of prep time required when getting ready for classes when I was teaching.
Interestingly, I did a few more today just so that my Canada Day tag will show posts all the way back to 2004. If you click the photo below from 2009, you will load this blog post and many others referencing CANADA DAY. (As the results will not fit on a single page, in the mid-point one must click 'older posts' in the footer to continue.)