On my knees on the workout mat...

So this isn't really a workout complete check in for today or anything. I haven't worked out today, but there's something that's been on my mind for a while now... I usually think about this after workouts, but I just haven't taken the time to write it down before...

I have a workout mat which I really love. It's so much better than being directly on the floor. But... I still sometimes that it's hard on my knees when I do half push ups, for example. Does anyone else feel like that too or is it only me? Sometimes I even tried having a pillow under my knees, but I try not to because it kinda feels like you're not supposed to do it like that, heh... Or does it matter?

What are your thoughts on this? :)