It is a free country, do what you like OP. However, I'll share my not very exciting tale.
I am a GP. I have worked as a hospital doctor in both obstetrics and paediatrics as part of my training. I have delivered babies, delivered antenatal care to women, attended post-natal clinics for women with gynaecological problems post childbirth, and looked after sickest of the sick babies in the neonatal intensive care unit. I was pretty sure I knew it all and was well-prepared for having a baby.
I did do NCT classes, as I don't know anyone in the area with babies and I did figure out that I might want some people to talk to afterwards, so I went from a social POV. I was, in all honesty, a bit of a know-it-all and corrected the NCT leader etc and probably gave off "I'm too good to be here, I know all this" type vibes, which in retrospect isn't a good attitude if you are trying to make friends! Luckily, they were quite forgiving.
I had a textbook pregnancy and birth, went home the next day. And was a gibbering, snivelling, wreck for at least the next 4 weeks, if not 8. And I had a perfectly healthy happy baby and very little in the way of gynaecological trauma to deal with. I was a ghost of my usual self. I had zero confidence in my own abilities to look after this little dude I'd created. I could barely leave the house, and didn't without my DH there to help.
If my HV had not called round, I don't know what I would have done. She gave me so much reassurance that what I was doing was right, told me to stop stressing when DS went a tiny tiny bit yellow and generally saved my sanity. DS is 8 months now and when I go every now and again to HV weighing clinic to say hello to her she always gives me a little knowing wink of "told you it'd work out alright, didn't I?".
As for the forgiving NCT group, we are all good friends. Most of us see each other once a week. I go to Rhyme Time, Baby Sensory and previously went to Waterbabies and Monkey Music. Of course it isn't fun for me well, Waterbabies was I suppose, but it isn't about me. Frankly, whilst classes haven't been running over the summer I have been going round the bend with boredom. DS just isn't that interactive yet. The days are so, so long if you have nothing to go out and do.
So, as PP have said, don't write anything off. You may think you know it all, as I did. You are in for an almighty shock when you do have a little one, just as I was.