Like Luke Skywalker you must learn patience. The work that you do sometimes take a long time to take effect. Some teams may be very reluctant to change work patterns and thought processes. Even in teams willing to learn and adapt, it takes time and several iterations to fine tune your agile work. And as long as the team is trying to adapt, them voicing frustration over the process is an asset – utilise it!
Then there may be teams or team members who complain, while also being reluctant to change. This can be very frustrating. Listen, but don’t let it get to you.
Things are never as easy as the agile evangelists will have you believe. Nothing is ever as simple as just going Scrum and things will be all peachy.
The reason your job exists is because going (and staying) agile is not easy!