Don't assume that because you opened up a pull request, that the author will accept it. There are many reasons that a maintainer might choose to not merge in your specific patch, many of which have nothing to do with you. If your patch isn't accepted, try to assume it's for a valid technical reason and not because the author hates you.

Don't get upset, rejection is normal

Sure sometimes my changes get rejected, but it almost always comes with a reason why and I can work together with the maintainer to come up with a sensible solution to my issue.