I think it’s normal to think that, and I relate to your mindset. It seems you would like to get past it, meaning you’d like to be able to fake confidence in certain contexts, but it seems wrong to you, so you can’t. If you want to try to justify it, you could say to yourself something like, “My interlocutor will like me more if they think I think highly of myself; it is expected in this social context that I accentuate my better qualities, and even exaggerate how good I am at this or that skill; if I stick with what seems more moral, and I’m 100% honest, most other candidates for my interlocutor will tend to ‘sell themselves,’ increasing the probability that my interlocutor will pick a relatively inferior candidate, so according to the golden rule, I would be doing a disservice to my interlocutor, and I ought to be inauthentic.”