What did you do differently before the decline happened

I found a very good topic on the other thread and I believe most people are very interested in it -- minimize the risk of lung function decline.

I did some research and found it's very common that the decline follows a staircase pattern. Lung function usually levels off for a period of time (could be months or years), and then a sudden sharp decline.

In many situations people had exacerbation and this is a well known issue, but sometimes the decline just happened out of blue and we don't know the rood cause.

Here I want to collect some information just in case we can find some clue. What did you change in the year of or one year before the decline happened to you? (For example, Tried new food? Exercised more? Moved into a new house? Water leak? etc. )