Why do you think law firms ask you these sorts of competency/general questions? After all, they obviously don't care in the slightest about your story of being under pressure because you lost your coursework, or of how you managed a bar on your own or whatever.
The story per se is irrelevant. What they want to see are your character traits. They want to see how you cope under pressure - because that's a situation you will definitely be facing if you work for them. They want to see how you deal with an unexpected challenge - because again, that's something you are likely to encounter. The story itself you are telling is not particularly relevant. What matters is that you structure your story in a way that clearly shows you have the values they are looking for in their question - planning, lateral thinking, coping under pressure, and so on.
When I say link back to the firm, I don't mean namedrop the firm. I mean have a look on the firm website, their promotional material, what they say at law fairs and so on. You'll notice a lot of firms have a series of buzzwords they clearly put a lot of importance on in their employees.
Linklaters call it their Agile Mindset Framework, each firm does it differently. Address some of those points/targets subtly in your answer.
Without this and some form of the STAR technique, people often just tell rambling stories in competency answers, which don't do well, as they often don't address the points that the firm is looking for.
