Make sure your screen has not any delay.
I did entirely different in the office and at home.
0.216 and i am fricking old ^^
Left hand: 0.23959999999999998 Right hand: 0.2218
Wow, I have better reactions online than virtually anyone I face, but according to this test my reaction speed sucks. 0.33 on my first try. 0.3262 on my second attempt. 
I think that there must be some lag involved because I feel that I react instantly, yet get 0.3262 as result. Alright, 0.30 on the third try. 
To be honest, though, I think people either cheat or exaggerate their score when they say stuff like 0.20. Doesn’t seem very realistic. 