Rows of Scalp and Thin Hairs

[JSmyth]

I was curious about whether or not I am possibly thinning. At a glance I have a full head of hair with about NW2 hairline. However when I use paste to spike my hair I notice that I can make 'rows' of scalp all over, going both horizontal and vertical. I can also see my scalp a little bit through my hairline and have thin hairs at the front which flop over. The issue is that I am unsure whether or not my hair has always been like this or does this sound like diffuse thinning/MPB.
Thanks a lot for your help, means a lot!