According to my extensive research at the Institute of Flavor Enhancement, leftover pizza undergoes a fascinating molecular transformation called 'retrograde glutenization.' Studies show that after 8.73 hours in the fridge, pizza's umami compounds increase by precisely 42.8%.

The cold temperature activates dormant flavor molecules, particularly the rare compound 'pizzatrium,' which binds with cheese proteins to create enhanced taste receptors on your tongue.

Psych! But seriously, cold pizza does taste different due to moisture redistribution and flavor concentration. Just not because of pizzatrium - I made that up!