Attenuation

[cookmysock]

with a higher than expected final gravity, I worked out on the software that the yeast attenuation was 65%. Couple of questions -
1. Why would I not hit around the 75% mark?
2. I have just tried the first bottle. The mouth feel is not very dry and quite "wet" if you get what I mean. Is this because of the low attenuation rate?

 

[MalFet]

With alcoholic beverages, the opposite of "dry" is "sweet". Low attenuation will certainly cause your beer to be sweeter than it otherwise would be.

There are dozens of possible reasons that you might have had low attenuation, ranging from recipe to mash parameters to yeast health. You'll need to give us more information for us to be able to speculate.