Mildly chuffed to see there is someone else out there like this; I'm the exact same way. I don't touch type properly, don't use home row, but type at a pretty decent clip when it's familiar - even code. Slow down quite a bit in new territory.
What sometimes gets me though - I think one word, but type another. It's almost always the same starting letter or letters though. It's like the muscle memory kicks in, but takes the wrong fork in the road or something. Very odd.
This happens to me all the time! “Thought” instead of “though” comes up often, but I know I’ll just type in completely different words than I meant to as well. I am always reading back anything I send a minute later, just to catch the silly mistakes and correct them. It is probably annoying for the people reading the newly-sent message, when it shifts around while they are reading it. Sorry!
What sometimes gets me though - I think one word, but type another. It's almost always the same starting letter or letters though. It's like the muscle memory kicks in, but takes the wrong fork in the road or something. Very odd.