When you look at your tank and see the individual critters crawling/swimming around doing their thing and you just kinda smile and think "yep, every second spent on that was well worth it". Greatest feeling ever. Even though my tank isn't done yet, seeing my HC starting to fill in well and seeing my few shrimp crawl around and my Espeis school with my pygmy corys is a great feeling of accomplishment. Feel free to share your experiences. 