Initially I was at my mouse's default which was 6000dpi. But after playing for a while people said to lower it, so I did... to 2400dpi which felt super slow at the time. After playing like that for a few months I decided to watch a bunch of shit on aiming. I turned my DPI down to 400 but noticed my sensitivity was still much higher than in the videos. What I didn't know was that my in game sense was set to 6 the whole time LOL. So somehow I was managing to play at 36,000dpi and 14,400dpi.
You gotta realize coming from 11 years of console only, any mouse movement felt far at the time.