Blaise is five when he first arrives in Britain. Previously, he and his mother and father lived in Italy, but that is before his father's dinner party. (It is before he and his mother floo to Paris to pick up a pair of expensive custom cufflinks for his father's birthday, before they return home late at night to find his father's body crumpled on the floor in a pool of blood, near the dinner table set with dessert plates.)
The look on his mother's face that night is one of his worst memories (pain and heartbreak and fear and absolute fury settle like a mask on her normally smiling face, and it is a long time before he can look at her without seeing those emotions sealing the cracks in her facade).
The next day, she is making plans to move to Britain - she tells him it is because she fears the killers will come back, but Blaise knows better, knows she has plans to kill them all - and within a week they have settled into their new home.
A year later, Blaise comes home in the afternoon, having been exploring Diagon Alley with Theo Nott, to see his mother standing with a man in the parlor, a ring glinting coldly on her finger. (Later that night, when the man has gone home, his mother tells him that he was one of father's friends. He looks at her sharp smile and glossy eyes, and Blaise knows she means killers.)
They get married within months, and then one day his new stepfather dies in a potions accident. (When the Aurors come, tears well in his mother's eyes, and her hands tremble, and the Aurors believe every honeyed word that comes out of her mouth.)
Her mother waits a while for her next victim, and she marries and kills him, too. The Aurors begin to pity her for her terrible luck. She marries and murders three more men in quick succession, and the rumors start and dies even quicker. (She tells him one night, when he's ten, and the Aurors have finally left, that this most recent victim is the last.)
He takes her hand between his, looks up at her beautiful face, which is unguarded and joyful for the first time in years, and tells her he's happy for her. (He's not: he's relieved that it's finally over.) She kisses him good night and sweeps out of his room.
He is thirteen when she marries again, ignorant of the warnings her newest husband receives regarding the bad luck of previous husbands. Blaise considers warning his newest stepfather himself, but doesn't when he sees how happy his mother is. He grows to love his stepfather, and each year that the man continues to live is better than the last.
He asks him once why he ignored the warnings, and his stepfather sits beside him and tells him that people are willing to do many things for love. (It hits Blaise then, as his stepfather claps him on the shoulder and walks away, that this man knows exactly what his mother has done. He knows, and he married her anyway.)
He remembers a conversation he overheard before his father died - not all of it, but he remembers the important parts - in which his father told his mother she was worth the risk. Blaise wonders how he never noticed the similarities between the two men. (He wonders if this is the reason his mother married again, but when he brings it up, her lips flatten in offense, and she snaps of course not , and he immediately apologises. It doesn't stop him from thinking it, because no one else he knows - or knows of - has ever reacted to a loved one's death in the same way she did.)
Eventually, he decides that it doesn't matter if those similarities had any influence in her choice; he won't love her less either way.
In third year, the Dementors linger around the castle, and whenever they come near him, he sees his mother's face, shattered by emotion, and he sees his father's lifeless body. He tells himself those memories are not as bad as other people's. (He thinks of how Haven hears her parents' last words, followed by their deaths, of how Neville can hear his parents' tortured screams, or how Theo sees his mother falling and breaking. In comparison, his memories are not nearly as bad to suffer through.)
It is not until after the Quidditch match, when he is sitting with all of his friends by Haven's bed in the hospital wing, that he voices these thoughts, and Haven and Theo both look up at him sharply. It is Neville who bumps their shoulders together and says "Just because your experiences are different - just because you weren't there - doesn't make them worth less, doesn't make you worthless."
"Suffering isn't something that can be compared," Haven adds, "because it's different for everyone."
Blaise didn't see his father die, but he comes to understand that that doesn't mean he's not allowed to suffer because of his past. He thinks that everyone deals with pain differently because everyone is different. He thinks that people are compared to each other enough already without adding in a comparison of their pain.