Even if your assigned gender is correct, GID can still creep up. While personal factors can play a role, society (including parents) can set up rules/norms/mores/laws that tend to condition certain responses, and if a particular person violates these standards, then that person is subject to adverse treatment that can condition dysfunctional feelings and behavior.
As for whether "mental conditioning" is a good thing, I would say it depends on the behavior or feeling that is being conditioned. The idea that hard work tends to be productive is a useful idea to condition, because it helps you remain motivated. The insistence idea that females are stronger than men, however, is counterproductive, just as the reverse is; the idea discourages men (just as the alternative does to women) from working as hard as they should (or at least as much as their counterparts) to develop and demonstrate their strength.
If you want to look at conditioning that is productive, you should look to factors that you can control and decide what you want to do with them. On the other hand, one should be wary of the "effect" of other factors, because many such pairings (such as gender and strength) lack a direct cause-and-effect relationship, the methodology can be flawed, and such pairings are not absolute truths (even if there is a cause-effect relationship).
To determine who you really are, you should try to ignore social roles (including family roles) and try to evaluate yourself on a more basic level. I don't know how this really works, but one approach is to ask yourself how you feel about your boy-bits. Does it seem reasonable for them to be a part of you (whether you are ashamed of, neutral to, or proud of them), or do they seem to be more like a mistake?
It is perfectly acceptable for you to be a man even if you violate 20%, 55%, or even 100% of social norms/stereotypes for a man, so do not be ruled by society's or your family's idea of what a man is supposed to be. Instead, you need to determine what a person should be, and do your best to be that kind of person, while still embracing the particular factors that make you unique.