Love this example! It really helps to be in a place longer than a month. You get into a nice routine and start to see things that you can never see when you are just on vacation.

A few edits to this one:

1. Instead of “have been a big dream,” you can say, “Since I was a teenager, my big dream has been to live in Medellin.”
2. “during my years of retire” can be, “during my retirement years” or simply, “in retirement.”

Medellin is beautiful! That sounds like a great dream.

Great example and perfect use of “come true”! (And if it’s true, congratulations!) A few other edits to the rest of your sentence:

1. We say “dream of” + -ing verb: “Since I was a child, I have always dreamed of having a big house.”
2. Make sure to put “come true” in the past tense: “Fortunately, this dream came true.”

Ah! I love that. Well, for me it was being a baseball player. But a lack of talent and lack of athleticism did me in.

Perfect example!