Why is the brush stroke not totally dark (Photoshop Elements)?

I use Photoshop Elements, and I haven’t changed anything that I know of, but for some reason, all of my brush strokes are semi-transparent. I have Opacity at 100% on everything and spacing at minimum. If I tap the left click to stroke it looks really transparent and when I move it seems to fade in. I’m using the same brush I’ve always used and it’s never done that.