I did PhD applications for maths and got into Oxford and Cambridge. I chose Oxford because the topic seemed more interesting. My friends won't shut up about how Cambridge and Trinity College is more prestigious for maths and that I 'made the wrong the decision'.

As ridiculous as it sounds, it's getting to me and driving me crazy. Their disappointment/upset is making me feel bad now, that I could have actually 'missed out'. I can't get it out of my mind and it's stressing me out to the point that I can't work or concentrate.

How do you cope with other people's opinions, and more generally about this whole university prestige bullshit? How does one silence the mind and be content...