some people genuinely cant be happy for others. and some are as envious as snakes
i entered the comments of
bobirjon's post to congratulate, and saw one guy questioning the impressiveness of the achievement. ucl is no doubt one of the leading unis in the world — literally the phone you are using was first invented by a ucl graduate as well as famous movies like opppenheimer, interstellar were directed by a ucl graduate.
to say getting into this selective school is not impressive, you need to have sucked in a lot of failures, often without any sign of success. its good that most people at least keep this to themselves.
still, learn to be happy for others and maybe get closer to them and seek guidance if they achieved what you would like to attain. and if not, simply ignore. no one misses your happiness for their success.