This episode was so-so for me. It had some funny moments. I like how they made fun of "Once" and got the stars of the movie in the episode. I Colm Meany. The signs and the sight gags were the funniest parts for me.
After Homer forgets about a father-son three-legged race at the Springfield Retirement Castle, "The Simpsons are going to..." Ireland, to a pub Grampa visited during World War II, so Grampa can have "one final drink" there - which turns into Homer and Grampa buying the pub.