A scene that crops up frequently is the one where the main purpose is for Character A to meet with Character B, and for Character B to tell Character A something that changes their perspective. So you write it - A bumps into B, they chit chat for a bit, then B tells A the relevant info, and A thinks differently.
That's fine. But what I see writers forget is that A can't just stand there like a lemon waiting for B to come along and tell them the relevant info. In other words, you as the writer have an agenda - that B passes on the info - but you've forgotten that A needs to have an agenda too.
If A doesn't have an agenda they can appear passive and one dimensional, which is a problem given we're usually trying to write active, multi-dimensional characters. The solution is to give A their own agenda.
For example, A might be on their way to an urgent doctor's appointment when they bump into B. They start the chit chat with B all the time wondering how quickly they can escape without appearing rude, then B starts to talk about something interesting, and the doctor's appointment goes out of A's head as their focus goes onto B's new information and what it implies.
It doesn't really matter what A's agenda is, what matters is that it's there. In effect, A having an agenda of their own brings in some conflict to the scene which otherwise lacks it, and by doing so, A appears active and multi-dimensional. What's more, you can usually add the relevant agenda with just a few additions so it's easy to do. Result all round!