I've been there. I may still be there. Don't most of us have to deal with "clients" in some sense, regardless of our position, regardless of whether employed or self-employed?
When I was a freelancer, there were times clients drove me nuts, mainly when it came time for payment. There were notable exceptions, of course.
Mainly, I think I enjoyed other people, i.e., clients, more in my freelance work than any other time. Being in charge of my own business gave me a certain sense of confidence, and of course, I was free of the office politics that can beat one up. It was also reassuring to know that if a day ever got too rough I could flip on the Turner Classic Movie channel and settle down with a nice g&t or something.
Potential clients were the worst. I had so many people "express interest" in using my services but who would never commit to an assignment. One kept coming back and coming back, and we'd have lunch after lunch to talk about his "needs," and oh, this time, he was ready, he'd have a contract for me next week. Finally I flat out told him to stop wasting my time, and well, I never heard from him again. Ha!
Then there are the kind who are never satisfied. One of my best paying clients kept revising the assignment needs, kept moving the ball, as they say, and then would blame me for not understanding the assignment. He paid me well and on time, even though he thought I was fucking up, so I'd just be all humble and say, Gosh, you sure are right. I messed that up. Oh, and your next check is due next week.