i wonder if it possible to increase your memory,thinking speed etc.

 

Practice and let neuroplasticity do the rest.

https://en.wikipedia.org/wiki/Neuroplasticity

I've had great success with avoiding products that claim to boost brain power. Each time I remember not to buy them, my intelligence is measurably higher.

Exercise and a good diet / hydration help, too

Get enough sleep. Just trust me on that one.

There are wakefulness promoters, but nothing like the fanciful Limitless pill.