The talking to oneself is a way to slightly increase memory capacity. It isn t abnormal, but the decreased memory capacity is. These are bad signs. Correction fluid is frankly more dangerous in the short run (liver toxicity). This can be tested with very simple liver function blood tests that are quite inexpensive. Assuming the liver is fine, there can be some brain damage from the typing fluid but that is NOT common. Short term changes in thinking from any drug that impairs the brain is somewhere between common to nearly universal (at the time of intoxication and withdrawal...lasting maybe 2 weeks). From marijuana most of it clears up rapidly. On long term use, and careful testing there is some residual (small) effects on mentation. It might come back in months, getting adjusted and learning ways to supplement memory like notes is a bit faster. Obviously these are reasons to never use again.