I used to be exactly like that, could even type blindfolded with my own weird way of typing. I eventually learned touch-typing (i.e. the correct way your teachers were trying to teach you) and a more ergonomic keyboard layout (Colemak), I haven’t gained any speed, but I do notice that I get a lot less strain on my wrists and fingers. So if typing is something you do a lot on a daily basis, then it’s worth learning to do it properly to not injure yourself in the long run.
I used to be exactly like that, could even type blindfolded with my own weird way of typing. I eventually learned touch-typing (i.e. the correct way your teachers were trying to teach you) and a more ergonomic keyboard layout (Colemak), I haven’t gained any speed, but I do notice that I get a lot less strain on my wrists and fingers. So if typing is something you do a lot on a daily basis, then it’s worth learning to do it properly to not injure yourself in the long run.