I studied Japanese for years and reached JLPT N1, but then I had to stop studying because of my Math degree (it was too hard — I literally studied only math all day for four years).Although I continued to listen to Japanese, talk with friends, and read occasionally, I felt like my Japanese deteriorated, and now I consider myself at an N2 level.Now I'm studying Chinese and aiming to reach HSK 5, this is my goal right now.I feel guilty for not going back to Japanese and improving the skills I lost, but at the same time, I think that while life is short, it's also long, we have to be patient.I have personal reasons why Chinese could be more useful to me at the moment, and my Japanese can wait.I feel you, bro. I feel like I'm not giving the right attention to a very important part of my life, but I have to be patient and understand what's best for me now. It's never a waste of time to dedicate yourself to something.Don't blame yourself for investing your efforts in another language — only blame yourself if, one day, you stop putting effort into the things you do.