Need suggestions: How to challenge your mind only using your mind ?!

That's a palindrome. Anagrams are different words made from the same letters. For example, "evil" is a palindrome of "live" and "vile" is an anagram.

Palindroms in English... Kayak, Racecar, etc...

As chess players these situations really calls for some blindfold practice, I guess.  I can´t play a whole game blindfolded, but going through some standard openings and see how far into the lines you can keep order of the visualized board can be fun.

Thanks all for the ideas, I notedd

try to think of a plausible way to find alien life.

amishelectrician wrote:

try to think of a plausible way to find alien life.

Will think about it tomorrow in history class

I don't know about mental games,lol.

But I would kind of relive things that I had done the day or week or even months before.  Thinking about it and coming up with things that I would have done different is quite entertaining,at least for me.

Does this make sense?

Try sleeping and dream until the plane departure i announced.

is ok, but im talking about a challenge for your mind, something that is like a hard puzzle but only in your mind

Try and solve the knights tour

Try remembering chessgames you previously studied.  Some games or at least positions from specific games I can recall and play out on a chessboard without a scoresheet.  And in the mind for that matter. 

You could also play in your mind certain endgames you remember from certain books.  The Botvinnik game where he sacked a knight later on against a long pawn chain, won a passed pawn, and elbowed out the black king to win, Morphy-Revierre (rook ending) and Morphy-Anderssen (queen ending where Morphy played the Evan's.  No I don't hate Morphy and in fact think he's really cool but some of his losses were quite interesting) are two of my personal favorites, especially variation A (Fine's BCE revised by Benko) from his Revierre game. 

Reflect on the principles of these games or play a mental chessgame against yourself.  Fischer used to do this and like they say emulating the greats is a good policy. 

The Botvinnik game, I forgot the opponent though:

multiply, start with two and keep multiplying by 2 again and again and see how far you can go. it would start like this: 2, 4, 8, 16, 32, 64, 128... (i know it up to the millions but i don't want to tell you the rest).

Once you get bored of that you can do 3. It would go like this: 3, 9, 27, 81...

then 5 and all the way up the prime numbers (i find those the most entertaning)

5 is easiest

You can try to ask yourself a question like: "What is a good deed?"

Then you formulate an answer. It's very important that you either say it, or are sure exactly what words you are using.

An answer could be: "A good deed is when you do something, which makes someone else happy, without necessary being good for you"

Now the fun part: You try to find examples, which refutes your answer.

An refutation of my answer could be:

"Is it a good deed to kill a random man, so I can feed a random dog? I make the dog happy and it doesn't necessary makes me happy, so according to my answer, it's a good deed. So my answer needs to be fixed".

It takes forever to get an answer which has no refutations (Sokrates and probably quite a few people after him tried, but did not publish any bulletfree answer), and if you get tired of the question, there is quite a few other philosofical questions.

Which came first chicken or the egg

Look at the people around you and try to imagine what their story is. i.e. what kind of job they have, etc. Then go strike up a conversation with them. (also makes for a good way to meet people and be more outgoing)

Mentally recite sequence of numbers like sequence of

prime numbers 1 3 5 7 11 13 17 ...

squared numbers 1 4 9 16 25 ...

nice idea, the max. consecutive checks record game Britton-Crouch ( P&D Knights, London 1984 ) came to my mind

Start writting that novel in your mind.