Yup you're not alone. After many years of developing and never using a whiteboard, my first attempt at a "whiteboard architecture talk" where I was forced to use a whiteboard was a 45min talk and I came out thinking it had gone quite well, looked back at the whiteboard and saw I had drawn a single box on it. Just one box with no label. I couldn't even remember what the box was supposed to signify.

Not everyone thinks visually. I'm also baffled when people ask for network layout diagrams or want to show me them. I just don't care about seeing that stuff in a diagram - it very seldom gives me information I feel I'm not getting somewhere else.

I've trained myself to do the whiteboard talk now because it seems to help some people. So if I'm communicating a design idea or whatever I'll often draw a diagram while I'm explaining it.