That's fantastic that he's finally found a love of writing and reading. It's certainly something to be encouraged. It's so true that the wrong kind of teaching can put them off learning and set them back. My youngest nearly got put off reading for life.

I was told it was common for kids to get letters flipped; b/d and p/q are common ones too. My youngest did that for a while. I can't remember if my eldest did. She may have briefly, it just took my youngest a bit longer to figure it out. I recall her teacher (a lovely woman) in reception trying to help the kids remember which way 'b' faced by saying that it has a belly.