You were hit by lightning and forgot everything about a given subject. Maybe a hundred chess games, a book or ten, a language, a trillion pi digits, formulas, viruses, flamenco dancing!? 
You remember all memory techniques and lost none of the skills involved. How would you start to use these to re-remember it all?
Just one language is an absolute no goā¦ first thing, re-memorize the Proto-Indo-European language tree. After that down the Italic and Germanic branches. Frequency dictionary for use with memory towns to get the first 200-300 words down. After that, kick back and watch some tv shows and movies in each language until things start making sense.
After that, itās time to regain those mental math skillsā¦ limited to vedic math, there are some other useful approaches but 80/20 hereā¦ you never know when you get struck by lightning again and have to redo the whole thing all over. Maybe also how to solve a Rubikās cube and how to solve it blindfolded. That and calendar calculation would nicely bridge the gap between mental math and memory techniques.
Should be enough tv by then, so traveling to different countries to actually make some use of the languagesā¦ turn that passive vocabulary āactive.ā 
If bored along the way, memorize subway networks of the big cities, so that you know where you are. Also, get some new memory palaces as I presume āremember all the memory techniques and lost none of the skillsā wouldnāt really include the old palaces, would it?
That would be my approach to get back on track as quick as possibleā¦ after that we can discuss Chinese, Hindi (basically, non-Latin script) and other topicsā¦
Ahahahaha !!! I havenāt laughed that hard in a long time!
I really like your adventure! This is so interesting to me. I would travel with you throughout this quest of yours, definitely! Vedic math is on my list now but I keep on pushing it back. A good lightning sure puts some different perspectives onto it all !
I am inspired by how big and diverse are the opened doors of memory techniques and your posts shows all the colors I had imagined and a couple more.
No way, you would never lose your palaces! But yes, youād have to repopulate them if stricked again.
When I think all this wouldnāt even be considered possible 15 years ago, in this civilisation.
Even calendar calculation now sounds like fun and feels more useful then I had imagined.
hahaha now that I think about it I would end up thanking the lightning
@GibtsDochGarNicht Thinking of how you would tackle Old English from the start with the memory techniques you know now got me to imagine this scenario
Well first off if I were to be struck by lightning, I would assume that God was pissed at me AGAIN. Then I would hope that those brain cells long since dead, dissolved in pure ethanol, would be resurrected a la Frankenstein (it Liiives Master, it LIVES!).
As to the Old English I would start very differently, I would compose an entire Mnemonic Alphabet for the language, each phoneme/syllable and dipthong would have its separate image and all common words or parts of words too.
If only you had made the perfect lists of these and had posted them on this forumā¦ Crossing my fingers. Ahahahaha Frankenstein !
p.s I forgot to mention that, in your case, the lightning made it so your mother tongue was Old English
Forget everything I learned in Spanish class from five or so years ago? Yes please! I hated that teacher!
Forget everything I learned about geography? Okay, letās see.
First Iād reconstruct the latitude and longitude reference points + the general locations of the continents. After that, Iād learn the locations of major countries and their capitals to not look like an idiot. Iād probably focus on the US states and European countries next, and then go by continent for the remaining countries and their capitals, perhaps using their shapes to help. Iād practice probably by plying those games that ask you to locate the countries + drawing maps of continents by memory. Repeat until the entire world map was memorized. Iād also memorize the locations of large rivers, landmarks, mountain ranges, etc. to not embarrass myself in public. Last, Iād probably focus on the Canadian provinces.
thatās so funny ! for me it was the opposite geography teacher made me quit geography all together Spanish teacher was cute and even though I almost failed I never stopped longing to learn Spanish, which I eventually did.
I have at last made peace with the past and geography is on my list and I will be starting from scratch so starting out with latitude and longitude references is seriously noted ! Studying geography a to Zedd, then go on to the Canadian provinces , sounds like a wise plan 