no one in this world can ever be selfless.
let me prove this fact to you.it can be easily proved using contradiction.
lets assume that there is a person who is totally selfless.this person always does things for others.but there is one question.why would he/she do something like this?
the answer is obvious.because it makes him/her happy by making others happy.but it also makes him/her happy.which means he/she is doing it for him/herself.that makes him/her selfish.
this cant be true(contradiction).hence our assumption is wrong.