I've had almost the opposite experience from you. I'd long embraced it as the correct word to use when referring to a person of unknown gender or to a hypothetical individual, but having to use it regarding real people caused me problems. When my wife became coworkers with a non-binary person and its usage came up every few days, the better I got at gendering them properly the worse I got at everyone else. First I started accidentally calling her other friends "they", and then I started sometimes referring to any woman as "they". Fortunately that coworker took a job elsewhere before I started referring to men as they too.