Nicotine is well established as a nootropic and use of it correlates with reduced incidence of dementia (even when corrected for mortality biases). I am at a really high risk for dementia and I keep trying to vape in hopes of that (possible) benefit but I keep forgetting to do it. Note that the logic for your health choices get weird when accounting for high odds of being a zombie after the age of 65. Plenty of room to dump externalities onto "zombie-you"