So I just swapped my keyboard back to the shitty, old, default, black dell one because I hated the F keys on my other keyboard.
After taking the keys out, giving them a good wash, then replacing them, I of course tested them by typing a few lines in notepad to see if everything checked out.
Whilst I was doing this, I realise I type in (what seems to me) a weird way. I use every finger on my left hand (thumb for alt, but not space bar) but only 2 fingers and the thumb on my right. I just found it weird because my right hand covers more of the keyboard yet I only use the index and middle fingers (thumb for space).
I'm right handed, and my left hand is starting to take over apparently. Perhaps this has something to do with the fact that I've usually got my right hand on the mouse?