Is it normal just forgeting what you are doing

So, I play Osu! and I'm quite good but for like a few months or so I am experiencing some strange things. For example (in Osu!) there are hit-circles, sliders and spinners. When I'm playing sometimes I just loose control of everything (I forget what I'm doing and why I do it) for like a half second or so and just ruins everything. I have experienced this in real life too but I thought it was only from the game. Any suggestions what it might be?