Curly hair becoming straighter?

So naturally my hair is/was/still kind of is super curly. About a year and a half ago, I started getting really into hair health. Making my own shampoos, deep conditioning, protein treatments, everything. So my hair got really healthy, and still is really healthy. (At one point I bleached my hair, and dyed it a tad too much, but that was about 1 year ago, and I only have new growth now.) It is super healthy looking and feeling now, but it has definitely lost curl. in fact, it's pretty straight at the top, and slowly starts to get really curly towards the bottom now. It's been very gradual, but I was wondering if maybe it was just the deep conditioning, and things like that that did it, or is it just something that happens? I miss how curly it used to be...