I learned Dutch, passed the state exams and obtained my citizenship in my late 30’s / early 40’s. I honestly didn’t find it any harder than learning when I was

I learned Dutch, passed the state exams and obtained my citizenship in my late 30’s / early 40’s. I honestly didn’t find it any harder than learning when I was younger, only that my life was very different (lots more demands, responsibilities and distractions). I haven’t picked up anything new since then really though, I guess you might count learning how to invest in stocks, due diligence, fundamental analysis but that’s not a huge subject like a language is.