The writer seems to have lost the plot around half-way through.

When Colm said he didn't want to be friends with Padraic anymore for the reason he gives, it looked like the film had dropped its theme statement and was setting up to go in that direction.

Colm regrets wasting his life hanging out with Padraic and his idle chatter. He could have done something more useful with his time and potential like writing music.

What if at the end of Good Will Hunting, Will decided to stay in Boston, continuing to work as a janitor and hang out with his construction worker friends, instead of going to California to pursue a job and his girlfriend who had just left? What if many years later as an old man, he regretted that decision?

Up until then, this movie was a pretty decent comedy. It was odd, kind of like Welcome to the Dollhouse. But then fingers started getting cut off, and it veered into horror movie territory.

Also, when Soibhan and everyone in the pub saw that he had cut off his finger, didn't they think Colm had lost his mind? Why didn't they treat that as an emergency and call for help? The people in the pub in the first half of the movie seemed to be friends concerned for each other's well-being. Then in the second half, they're totally a-OK with letting Colm play his fiddle with blood splattering all over the table from his severed fingers. The movie had lost all consistency!