I first played around Oct of '12
I randomly heard about @xcom, but never got around to playing it because it was closed source, same deal with incursion (right name? the D20 roguelike), then found cataclysm, which wasnāt technically open source (no license), but whales encouraged modding and made the source available at least.
I vividly remember running around totally confused my first game or two, and being rewarded for doing things that made sense, like carefully sneaking into houses, picking clothing based on carrying capacity, and yes kiting zombies into junk to slow them down.
I progressed to surviving for a bit, joined the whalesdev forums, and got hooked on vehicles. I decided any decent apocalypse should have bicycles, and the rest is history.