I've been working in customer support for three years and I absolutely despise people in that job that don't try their best to help. This is their job, and if it's so bad they can't be assed to do it right they should work at another place. Sure, many customers are clueless assholes. But if I come up to them with all the respect and try to lay down my issue I don't want to get treated like shit, no matter how hard their day was.

If anything, my experience in this job made me less tolerant towards incompetent or disrespectful people.