If its greatly positive than even slight negative points would mean nothind, vise versa for those with highly negative perceptions. This is known as looking at someone through a coloured lens; now depending on how stubborn your natural character is and your level of bias, this isn't likly to change no matter what he/she does say/do.
Regardless of this, you should not impose these perceptions on other people let alone the person in question - unless you have a valid point to put across. These are your personal opinions brought up from your own conclusions, you should consider if you are being fair by being so biased towards them. If you've taken the care to build up such strong emotions; have you taken the care to step back and assess everything, which isn't just laid infront of you.
Before you judge, take a look at the other layers