If you avoid talking to the person who shows romantic interest in you, you will never reach the 3-6 month milestone ever - that part seems obvious.

People do not know about your 3-6 month milestone criterion. That is why they make assumptions about your lack of interest. 3-6 months is totally reasonable, but to reach the milestone, you need to at least keep talking to the person.

You also deny the possibility that the person who shows interest in you might indeed be interested with you. (??) So why do they show interest in you? to practice their people skills on you??

In other words, that part needs to be stopped ASAP. If a person shows interest in you, and you deny the possibility that the interest might be of a romantic nature (I do see how you would do that and I tend to underestimate male interest as well, unless presented with crystal clear evidence of such interest), you should at least grant the possibility that the person has SOME interest in you, because otherwise the behavior of the person who shows some interest in you is completely unexplainable. Since you describe it that happens WHENEVER somebody shows interest with you, it means that there has been a succession of people who have showed some interest with you. It is impossible that the behavior of all those people, in succession, was completely unexplainable. One - perhaps, two - maybe, many - out of the question. Right?

So, if there are people who show interest in you, not necessarily of the romantic kind, you should not stop talking to them - you should continue talking to them until you reach your 3-6 month milestone. Also, at some point you may want to inform them about the 3-6 month milestone.

Good luck!