Plus it's embarassing when you have house guests.
This past weekend I installed epoxy shower grout in between our 2 x 2 inch shower floor tiles.
With a little help from the tecnhical support line of the company that makes the grout I was able to do this project in less than 2 hours (that includes prep, install, and cleanup).
And I was a little under the gun since it was 7 pm when I started, primarily because I put my daughers to bed at night :)
If you want grout that never needs sealed and does the best job at resisting stains & mold this is the way to go. Since I'm in the rental home business this was a test run to
1. see if it was hard to install