I think my first time playing Doom was around 2011 (I was 9 during that year), so yea, I'm kind of new here.
I played it through a Flash game on a CoolMathGames-esque website. It was called the "Doom Triple Pack", which was a port of the shareware versions of Doom, Heretic and Hexen into Adobe Flash. I barely made it far into the levels though; I think I gave up at E1M4, I think? I never got through E1M1 in Heretic, nor MAP01 in Hexen, however. I remember getting scared at E1M3's blue keycard trap, heh.