Well. Three things for me really.
1. The obvious- increased typing speed (accompanied by decreased accuracy and actually a decline in the active vocabulary; people in mudland prefer short simple words
).
2. Increased understanding of other cultures. Being able to simultaneously talk to people physically located in europe, america and australia (while sitting in Asia) is something that can only happen in muds. Understanding how the world thinks and feels about something and understanding what makes people tick is a really interesting pastime and its fascinating to make friends across continents , languages and cultures.
3. Arguably the MOST important, however, is an increase in the social skills (apart from the general sociability- that DID decline). I have headed two clans in DE and run the Mentor (assistance to new players) and RP programs of my mud and have done so for the last oh close to a decade now. If I look back at it, this has changed a few things about me,
a. Leadership. How to inspire a bunch of people (unknown to each other and who are not given any meaningful rewards or payment) to cooperate make them do what you want. In my RL job I handle large teams of workers, but I started handling people on a large scale in muds. At the same time, I have become more office politics crazy. We all know that muds can be really politically charged places with some players semi=convinced that all/most of the imms in a game are nuts
Being able to understand peoples' motivations, identify allies and channelise these interests into successful work and cope with all kinds of political undercurrents has helped me to not only survive in some of the more politically charged units I worked in and also get some amount of larger advocacy work stated IRL.
b. Patience. Stuff never really works the way you want to in a mud (I am talking about the political and social aspects of mudding again). You learn to compromise, adjust, adapt and not lose track of your goal.
c. Thinking on your feet. someone pointed out earlier that being a RPer helped them to adlib their lines in drama. I would also point out it helped me to not panic in case something unexpected (and unpleasant) happened at work and come up with an immediate way to curtail the damage.
4. I guess I can sneak in a fourth point. I met my fiance in a mud. I suppose that makes THAT the greatest help muds have given me