I never used to put too much weight on first impressions. I always used to try to build an impression of someone by interacting with them over time. I did not want to rush to judgement and I wanted to give people the benefit of the doubt.
Lately I’ve been thinking I should come to conclusions about people much sooner. Forming a first impression has become important to me now. Time is precious and I do not want to waste a lot of it giving people the benefit of the doubt when they don’t deserve it.