Final answer:
The individual did a stint in jail, which means a period of time spent in prison, due to the theft of paintings from a museum. The sentence reflects on the gravity of the crime and its consequences, as well as the introspection experienced during his time in jail.
Step-by-step explanation:
He did a stint in jail for stealing the paintings from the museum.
In this context, the word stint refers to a period of time spent in a particular activity or place, which in the sentence would be a duration of imprisonment. The sentence implies that the individual served time in jail as a consequence of his illegal activity, specifically the theft of artwork from a museum. The experience and consequences of this action seem to have had a profound effect on him, giving him time to reflect on his actions and their impact on his future.
The passages you've included describe a person who appears to be deeply contemplative about their criminal actions, the gravity of the situation hitting them as they hear the everyday sounds of life outside their jail window. This reflection on past choices and the resulting imprisonment for crimes against a museum, possibly related to the portrayal of British soldiers, adds depth to the individual's narrative and highlights the serious repercussions of such actions.