Today I've returned to osu! after one year hiatus as this graph shows:
http://i.imgur.com/PmPICOX.png (I enlarged it a bit too much to embed it)
I don't remember exactly which was the reason of leaving, maybe I was too busy or I just got bored of playing the same songs over and over (and too lazy to look for new ones). However, what actually *forced* me to leave was my old mouse, with that mouse the cursor used to go on their own from time to time, which made it useless for osu! and nearly caused some problems on games like PayDay 2 (just imagine that you want to kill a cop and you shot a window instead. Alarm buzzes and heist failed. I was very close to that situation).
Today I've purchased a brand new headset and mouse and my return felt really nostalgic I should have purchased them before. All those songs that I almost forgot... Wonderful!
The motivation that made me discover and play this game for the first time is the same that keeps me playing it when I can, and it hasn't changed in all this time. I play osu! because it's a great opportunity to listen your favourite songs while enjoying a good game.
I really like to listen music, however, just listening music isn't enough for me. Some people close their eyes to enjoy the melody. I can't do that, it doesn't satisfies me to just listen it, but listening music as BGM while doing something else is ok. Actually, many people listen music while in the train, browsing the net, reading and many other activities. Sadly, here it is the cruel irony, there are only a few activities that I can combine with a background music. I can't listen it in the train because I want to save as much battery and mobile data as possible (and I don't have any ear plugs right now). I can't listen it while browsing the net nor reading an article because it distracts me...
In conclusion, osu! is one of the few activities that allows me to fully enjoy listening to music, and I'm very glad I can play it again.