How do you cope with extremely insistent people?

[BrianSoddingBoru4]

Do you have someone close to you, who insists so much that you should do something you really don't want to do? What if they don't agree to disagree and you're not dependent on them? 
I find it easier to end the conversation if the insistent person is not polite, because I could end the conversation by pointing out they're disrespecting me. But if they're polite, how could I end the conversation? Should I just tell them I don't wanna talk about the subject anymore every time they bring it up? Should I leave?

"I have to pee" and never come back.

I strongly support this option.  Climbing out of a bathroom window has gotten me out of more than one uncomfortable situation.

Boru

[Der/die AtheistIn]

Der/Die, you need assertiveness training. I'm sure such classes will be available at you uni.

You are basically being bullied and you really need to put an end to it. Your life is your life and you need to get comfortable telling people that in no uncertain terms.

No, I'm not bullied. The insistent people in my life (besides my father sometimes) are insisting so much because they want what they think it's best for me. But thank you for your advice, I will consider taking assertiveness training.

[no one]

I tell them I'm not interested.

[Acrobat]

Do you have someone close to you, who insists so much that you should do something you really don't want to do? What if they don't agree to disagree and you're not dependent on them? 
I find it easier to end the conversation if the insistent person is not polite, because I could end the conversation by pointing out they're disrespecting me. But if they're polite, how could I end the conversation? Should I just tell them I don't wanna talk about the subject anymore every time they bring it up? Should I leave?

If people are continually being over insistent with you, it's likely because they see you as weak and maleable. If you've continually gave in to their insistent demands, your basically rewarding their behavior, causing it to repeat again.

Try being more direct, and keeping you feet firmly planted. Don't overly justify your Nos. Don't give them room to argue, and be honest.

I have an extremely insistent mother in law, who used to people giving in, but that's changed when she dealing with me, because she's learned that when I saw no, it means no. Her throwing a tantrum isn't going to change it, and our relationship has been the better for it.

[tackattack]

Queue commercial monologue voice over:
" Are you always the "nice" person in every group you're in? Do you have trouble saying no to people? When someone asks you how you are do you only have "OK" or "good, HRU" as an answer? Well then you might be faking it. No I'm not talking about faking the big O, I'm talking about being disingenuous with people. No one should matter more to you than you, until you have kids who will absorb your entire life. Time is short here and do you really have time to fake social interactions to navigate the social ebbs and flows of life?
What do you do about it.... THIS, for a special discount today we're offering you your very own....mute button!
That's right Be completely oblivious to insistent people, by completely ignoring what they say. What do you do when they get irate about you ignoring them, ignore them some more!
Comes with 1 free spine"

That's right, when someone really wants to talk to you about something, they do it calmly and rationally. I'd try ignoring them, waiting for their reaction that you're not listening to them, and come at you calmly. I'd start that conversation with, "I ignored you because you really didn't have anything to say that was important to me, see I'm..... and you want me to .... and I could do .... if ..... because that's how interactions work"

The twice ignore has worked for me on several occasions, plus if comes with the inherent knowledge that anytime it gets to be too emotionally heated, they know you'll just tune out.