I know it's called change but forget vs I know it's called change but i forgot

Some examples from the web:

• I know it's called a bed-and-breakfast, but missing dinner is a definite bust.
• I know it's an inconvenient truth, but it's called global warming.
• But I always know it's called pastrami.
• I know perfectly well what it's called, Lieutenant.
• Now I know why it's called a blood drive.
• In its native language, it's called the Diviner, one of many little details I know about this thing.
• Fortunately, not many people I know read "Time Magazine", or whatever it's called.
• I know a nice castle inn now it's called paradise
• You know it's called a brief, right?
• I know what it's called, and children born with it have a 40% chance of developing cancer by the time that they' in their 20s.
• Okay, it's called itself a nation-state for the last hundred years, but everyone who knows anything about China knows it's a lot older than this.
• How should I know what it's called?
• I know a game we can play. It's called who would you save in a sinking canoe?
• Karev knows it, and I know it.
• But - but I know it is - I know it is a lot.
• I know it's been a long time and I know it's impossible.
• I know... I know it's a needlessly vilified procedure, but one that has hopefully cured your addiction.
• And I know - I know it doesn't make sense.
• Now, I know. I know it isn't difficult.
• I know it's been difficult.

Some examples from the web:

• But I always know it's called pastrami.
• I know it's called a bed-and-breakfast, but missing dinner is a definite bust.
• I know it's an inconvenient truth, but it's called global warming.
• But I know it's a pseudonym.
• But I know it hurts, Duke.
• But I know it's important to Phoebe.
• But I know it will not be forgotten.
• I know it's last minute, but I really want this.
• But I know it's there because you sat on my knee when the doctor stitched it.
• But I know it was just an optical illusion.
• But I know it's nothing.
• But I know it wasn't a mistake.
• Everybody may not, but I know it.
• I know it drives him crazy, but I did it anyway.
• I know it's crazy because it came into existence... but I guess what would have been his voice.
• Or I saw his shoes, but I know it was him.
• But I wouldn't constantly order anchovy pizza, I know it tastes bad.
• But I know it doesn't.
• They haven't said why but I know it's Yvon.
• But I know it meant a lot to you.