The digital equivalent of "walking uphill both ways in the snow." These coding veterans had to squeeze every last bit of performance from machines with less memory than your coffee maker has today.
Back when RAM cost more than gold by weight, these legends were performing bit-packing wizardry—cramming 8 boolean values into a single byte instead of wasting 8 whole bytes like some spoiled modern developer. Sure it was slower, but when your entire computer had 64KB of memory, you didn't have the luxury of clean code.
Meanwhile, junior devs are complaining that their 32GB RAM MacBook Pro is "literally unusable" because Slack and Chrome are running at the same time.