I was told that I was a "celiac" as an infant, but it went away. How can that be?

Probably not so. Celiac disease is a lifelong process that does not go away. The diagnosis of "Celiac" was overused many years ago to explain why some babies were colicky, but it was probably not a valid diagnosis. See the discussion in the previous paragraph about wheat allergy. I have been told that I have a milk allergy. Why can I have some milk products without problems but not others?

People may not tolerate milk and milk products because they are Lactose intolerant or because they have a milk protein allergy. Lactose intolerance by far is the more common problem. People who are Lactose intolerant may have symptoms when they ingest foods containing a large amount of Lactose and not have symptoms when they ingest foods which contain a little bit of Lactose. People who are allergic to bovine (cow) milk protein may be able to eat milk products derived from goat milk, llama milk, or other non-bovine sources.