This is perhaps best understood as a commentary on the use of socially accepted mind-altering drugs, the most famous of which are probably Prozac and Ritalin. Note how the lyrics say it "makes me happy" and "now I'm awesome" which strongly suggest it affects the user's mood.
The literal meaning of "truthagen" would be something that generates truth, which while nonsensical is generally positive-sounding. This term is probably a further commentary on the nonsensical names of designer drugs such as the aforementioned Prozac and Ritalin.
Lyrics from the song;
“Truthagen truthagen truthagen makes me happy!
My mom got me Truthagen.
Truthagen…?
Now I’m awesome!
Wow!
We have it for lunch and tea every day!
Truthagen…”
Truthogen is a drug, said in the album "Truth of the world" in the lyrics of the songs "Max is stable", "Hey boys and girls", "infotainmentology" and "Chemical Miracle".
It's a fictional drug that has been created by the band Evermore. It's said to cure dizziness and tiredness.
A bath consisting of a variety of slats, oils, soaps or any other added ingredients such as fruits, milks, herbs or any other spices for health or beautifying benifits.
She brought home alot of stuff and took it to the bathroom. She must be taking a witch bath.
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.