Fish oil: Is extremely good for everything. Most people in the western world have a diet that is deficient in fish... what's really deficient is EPA/DHA. They're fatty acids that are widely used in your body, and especially in your brain. They stablise neuronal membranes, from memory. Studies show that it's effective at combating depression and memory problems.
Piracetam: Where to start... this is a wonder drug. The first of the so-called "nootropics". Though the exact mechanism is unknown, it appears to focus on ion channels. VERY low toxicity (e.g. no LD50 is known for piracetam). There is some mild instant effect (the so-called 'fast effect'), but the best benefits build over a period of 2 or more weeks of every-day usage (the 'slow effect'). Increases memory capacity and executive functioning generally. Also does great things when combined with pills.... seems to increase the perception of the pills effects. Significantly potentiates tryptamine hallucinogens.
Selegiline is an irreversible (suicide) inhibitor of MAOB. Thus it raises brain levels of dopamine and phenethylamine. Furthermore it appears to interfere with apoptosis signalling, thus inhibiting neuronal cell death. The later mechanism of action appears to be independent of the MAOB inhibition, and seems to be related to the fact that it is a propargylamine compound. Selegiline is metabolised to l-methamphetamine and l-amphetamine, which inhibit the reuptake of dopamine. (Selegiline won't get you high however. the 'fun' methamphetamine is d-amphetamine and d-methamphetamine. l-methamphetamine is good as a nasal decongestant, and not much else). Net result is that (taken over a period of a few weeks) one's brain feels remarkably sharper, with a much better memory. If taken over a VERY long period (decades), it can prevent parkinson's disease. I think it also acts to prevent excitotoxicity.
Acetyl-l-carnitine (ALCAR) is important in mitochondrial energy processes. It is used for shuttling lipids into the mitochondria (from memory). May assist in fat loss, but ultimately increases energy production in neurons, and appears to increase memory function.
ALA (alpha lipoic acid) is produced naturally by your body, but in relatively small amounts. Again, important in the energy cycle. Increases glucose uptake into cells, and is an EXTREMELY powerful antioxidant that is both water and fat soluble, so it gets everywhere.
The ALA + ALCAR is extremely synergistic; studies show that aged rats given the combination behave, on many memory and learning tests, much more like young rats
As you might be able to tell, I like having a sharp brain. I'm lazy as hell with uni, and I can cram more information into my brain in a smaller time period. My marks have certainly improved as a result, though arguably if I took more time before exams I'd still achieve the better results anyway.