Just try the damn brocolli.
Sometimes, people try to get me to do or try things which, in my estimation, it would probably be good for me to do/try.
In such cases, I refuse to do or try these things. In fact, I refuse even more vehemently and consistently than when people try to get me to do or try things that I expect to dislike, or that I really don’t think are good ideas. In fact, I think such cases—when people are trying to get me to do things that I think might be good ideas or that I think I might like—are the cases when it’s especially important to consistently and credibly refuse.
“Why??”, you ask?
First, because I definitely do not want to establish the precedent that I can be talked into things. (No, I do not think that “taking ideas seriously” is mostly—much less entirely—a good trait.) This would give people an incentive to try and talk me into things; I don’t want that.
(Aside: a big part of the problem is that this precedent-setting, and resulting perceived incentives, occur even if I decide to do or try the thing for totally unrelated reasons; protestations of “no, I’m not doing this because you told me I should!” are obviously useless.)
(Naturally, people who know/recognize and expect this pattern may perceive a way to manipulate me, via “reverse psychology”; fortunately, defenses against this sort of thing are fairly easy—things like “on a randomly determined subset of occasions, break this pattern”, etc.)
Second, because cases when I think a thing might be a good idea, or I might enjoy it, are precisely those cases when I am most susceptible to being persuaded to do/try a thing which, on reflection, is not actually a good idea/enjoyable, and to subsequently false convincing myself that it is a good idea or that I do enjoy it—in short, the danger is greatest, then, of social pressure / social proof overriding my own judgment. Thus it’s most critical, at such times, to firmly refuse.
P.S.: There are some people whom I trust to such a degree—of whom I am so certain that they have my best interests in mind and that they know me well enough that their model of my preferences and so on is accurate—that if they suggest something to me, then the reasoning I outlined above is inapplicable. There are very, very few such people. No one who has known me for less than a decade could possibly be included in that set.