My first (childhood) computer was a 486 (DX I think?). Pentiums were already out, even PIIs maybe. The LEDs on the front (remember those?) said "100", but I was always suspicious of these, because my computer seemed a _lot_ slower (at playing games – what else) than my friend's 133MHz... But his was a Pentium(!), so I never got to the bottom of it.
For the record I needed to downscale Doom to about a 1/2 window (running in DOS) to have it run at a decent framerate. Can't have been 100MHz, right? Does anyone here have a comparable benchmark of a "true" 100MHz 486 I can compare with?
Thus began my fascination with computers. Booting up DOS in some low-memory mode in order to squeeze every CPU cycle out of that thing. Working within constraints taught me a lot.
I didn't have internet at the time, but this thing had a 14.4k modem that I tried to get running. When the modem was in use, the mouse froze (and vice-versa). They were on the same IRQ interrupt jumper I think. I ended up frying the motherboard trying to fix this issue. I didn't have a computer for a while, but after lots of pleading and my parents seeing that I was serious about this, they eventually got me a Pentium 2 (450MHz or so!). But alas, it had a Voodoo Banshee video card (which had notoriously-bad drivers which often simply hard crashed). Alas, working within another constraint...