A question about Depression

So, for the people who know me here, i was diagnosed with major depression a few yeas back.

I was at the lowest i could have ever truly been.

I really don't understand how just one change in job last year, made it practically go away (As well as a change in medication I suppose)

It doesn't make sense at all. I am accepting that i'm more happy and I'm so grateful it tuned out this way, but seriously, how could it have changed to quickly from being so down????

I'm stumped and i'm scared that as it went away so quickly, it could come back again just as fast.

I'm so confused and don't understand at all.

Anyone know??

I don't have a clue sorry qwerky. However enjoy it - don't overthink it (I know that's not good. lol). All the best