I think it differs between each person.. although you're better than most people. I can never my Cs, Ps right, also I can never get out words that start with 2 constants, followed by a vowel (e.g. crumble, professional, premium, trouble.) People ask me all the time why I did that and it used to put me in a bad mood, eventually I got bored of people asking me the same questions and I just replied with a a shrug and said "I don't know.. it just happens." and people didn't think too much of it.