How old is too old to learn Japanese well enough to have meaningful conversations?
I am not even dreaming of learning any language fluently at my age however. In my opinion, 27 is generally too old to learn a language, or anything not related to your specialization for that matter, because your brain plasticity is non-existent at that point.
I spent 2 months learning hira/katakana and can barely read manga with furigana (don't understand meaning), and currently learn kanji with flashcards. However, my progress is extremely slow. I thought I made progress learning kana but after starting radical/kanji I came to the brutal realisation that my brain might be too old for such complexities, even though I work in CS/academia. Its funny how fast one peaks and goes past it without even realising.
Is it foolish at my age, 31, to tackle new language especially one as different from my native language (English) as Japanese? Assuming I manage to learn Japanese, I will already be too old to travel by the time I learn it, late 30s maybe even 40s, so is it worth it?