What does "good" mean anyways?

I am not quite sure what a "good" time is for an 400 or 800 meter swim, but I do know that I felt really good tonight after completing 400 + 400 meters (to equal 800, in case you didn't know!). Coach Cox asked us to time ourselves on the 800, but being gone for 2 weeks I wasn't sure how I felt about this so I timed myself on the 400 (which I thought was aspirational in and of itself) and then took a break and timed the remaining 400. I am proud to say that a) I did not die, b) I didn't drink half the pool as I thought, c) I actually free-styled the entire thing!! and d) did it in a reasonable time!! (I think) Those of you who know swim times can tell me what's reasonable, but my 400 meter was 9min 41 seconds and my 800 was 19min 34sec. Of course, this may change on Thursday when I time the entire 800 meters (no 5 min break at the half way point), but tonight I was proud of myself! Sometimes ya just gotta give yourself a pat on the back...