I have never met an Aries or Taurus that I ever felt like I could truly get to know. Our personalities just seem to clash. Based on my chart, why might this be?
The most likely explanation is confirmation bias. You believe you'll always have a personality clash with people whose sun sign is Aries or Taurus, so you pounce on every shred of "proof" for that and ignore everything that contradicts that belief. Maybe there were one or two Aries/Taurus people you didn't get along with, so you assume that's true of all. Ask yourself these questions:
Do you find everyone who is not an Aries or Taurus easy to get to know?
Do you know the sun sign of everyone you interact with?
Have you ever found out, after getting to know someone, that they were an Aries or Taurus?
Have you ever found anyone who is not an Aries or Taurus hard to get to know?
Have you ever, not knowing someone's sun sign, assumed they must be an Aries or Taurus because you felt you couldn't get to know them?
Have you heard that Libras don't get along with Arieses or Tauruses?
Finally, how old are these people you're finding hard to get to know? Are they all your age, give or take a year, year and a half? Or are you also having this experience with much older and much younger people?
Only the last might have some genuine astrological validity, but I won't go into it without you joining the dialog.