This is Sergei Vasilyevich Avdeyev. He is a time traveller.
Albert Einstein’s special theory of relativity states that the faster you travel, the slower time runs.
Sergei Avdeyev spent 748 days on the Mir space station travelling at an average speed of 17,000mph so for him time is about 20 milliseconds behind everyone else on Earth.
Put another way, Sergei Avdeyev is 20 milliseconds younger than he would have been if he had never travelled in space.