Are you cheerful?
In Acts 24:10 Paul makes his legal defense by first pointing out that he is the more cheerful. The word he uses is unique to the book of Acts and so gives us a perspective on the unique agenda of this book of the Bible.
The context of this word is that the prosecutor has made his opening statement by portraying Paul as angry and bitter. According to them he is trying to stir up strife, he is a "mover of sedition", and he is a ringleader of this angry sect of the Nazarenes who are still angry and bitter over Jesus being put to death over twenty years ago. They still just can't get over it, and of course that was the Romans who put Jesus to death. This is how Satan wants to portray Christians.
Take a look at all protestors around the earth whether in the US, or Iran, or China, or wherever. They are angry. They are focused on leaders who are corrupt, who lied, who took bribes, and who behaved unjustly. In every case they are focused on the faults of man who has sinned and fallen short of the glory of God.
Paul and the book of Acts is making a contrast between them and Christians. We are not bitter over Jesus' being put to death because we preach the resurrection from the dead. We are not focused on the failings of man, but rather on Jesus Christ who is Lord of all and that is why we are cheerful. We have seen the path that leads to victory and we are on that path. Paul was well aware of their failings and sins, he was calling on them to repent. But instead of being someone thrashing around in the water drowning, he is the one in the boat throwing them a life preserver.