Certainly a boost of confidence.
Osu is the first thing I have ever decided (or driven by interest) to invest a large amount of time, and saw some positive feedback. More peculiarly, it is not only beyond the surveillence of my parents, but an active rebellion towards the dillema that there are much more things I should do.
Many visible breakthroughs, and many invisible growth. That makes me understand that such mode of studying is more expansive and replicable in other fields. It provided a lot of confidence towards other difficulties of life.
Yet it also is a double edged sword, that you try to escape from life and find refuge in this game that gives you cerntain sense of success. It is very elusive, and it can be consciously captured. Therefore the influence perhaps is not as significant as one imagines.

I found a close connection between dancing and Osu!:
Osu! indeed is a form of dancing. A good dancing requires good choreography, which translates to map in Osu!. It also demands free form of expression by the dancer; a high demand in flexibility, in explosive expression, and precision in beat, which all of them can find expression in osu.
What is the essential difference?
There are quite some:
First of all, we only use parts of our bodies, in Osu!. Primarily upper body, and the legs do want to join, yet they are considered distractions most of the times so their demands are not met most of the time.
There is also less creative expression, for the distance between choreography and dancing in Osu! is quite distant: mapping is a tedious process and is very demanding. While the body, while trapped in the arms and legs and hips and necks, are surprisingly creative precisely because of the restriction that is imposed upon it.
Osu! also demands certain bpm requirements. For fingers are smaller entities than arms and legs, we are able to dance along with songs that is higher in BPM, averaging for an experienced player ranging from 160-210 (mere speculation so no statistical evidence) While dancing 160bpm can be difficult, it is easy for Osu! players to carry it out. The difference the bpm makes is that Osu! players can more freely investigate music genres that are higher in BPM, such as drum and bass, speedcore, that is more ryhthm oriented.
That being said, the reason I came up with this conclusion is that I found myself naturally more comfortable with dancing than other entertainment, and I really believe that it is a passion that is developed in Osu! that has been translated to dancing. Dancing is a lot of fun, even if you don't know the music at all.
Certainly knowing the music brings more fun, but the nature of the game made the techniques more universal than the maps, that we don't really need to learn specific maps (i.e. choreography or song) in order to dance. Therefore, I am perhaps more comfortable than most people in the club to dance to music that I have never heard about.