'I can teach you to stopper death.'
It is said that the eyes are windows to the soul: Snape's eyes look like dark tunnels and there is a reason for this.
No one really believes that Snape hates Harry Potter just because James Potter once saved his life; even though this is, in fact, close to being the truth.
For better or worse a decision was taken to protect the innocent; and so James's memories of finding Remus digging a hole through Severus's chest were 'adjusted'.
Each time it becomes harder for Dumbledore to force Snape to drink the potions and each time he does it anyway; because there is still so much more to be done.
Retiring at night, Snape changes into nightwear partly in vain hopes of sleeping and partly because, these days, his skin feels much too tight.
It is highly unlikely that those who accuse Snape of having no heart will ever suspect that this might actually be true.
Ultimately Dumbledore will betray his tool: his victim, who can refuse him nothing.
Sever us, Severus, please.
If you're still wondering what this is about, please note the title and the initial letters,
Sorry. Sometimes the bunny wins.