Do you have evidence that it is or is not inherent? For evidence of gayness being inborn there is the digit ratio where if you scroll down to sexual orientation you'll see that lesbians have a lower average digit ratio. This has been suggested to be affected by androgens like testosterone while in the uterus. This is evidence that sexuality is inborn. If true the obvious parallel is that a person can no more change their sexuality than choose to have one finger grow more than the other.
Edit: Having just looked around, It seems there is a long list of differences between homosexual and heterosexual humans. This is very strong evidence that people are born with their sexuality.
Edit 2: is that a downvote for going to close to the realms of politics? I'm still getting used to the conventions around here
The list you mention is not very strong evidence that "people are born with their sexuality". It's a list of correlations of varying quality and effect size that is subject to strong publication bias. More importantly, all of these correlations are perfectly compatible with the possibility that genetic/prenatal factors only partially influence one's sexual orientation rather than completely determine it.
Please read the section on twin studies that opens the Wiki page you referenced. The epidemiological twin studies are probably the strongest evidence we currently have, and they suggest that genetic factors play a role but do not determine sexual orientation.
What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.