A euphemism for penis or dick. Along with being a slight dig at whoever it's used against thanks to the connotations of baloney (cheap, unwanted, undesirable, etc.).
Saying this will also immediately make you friends with any and all weebs who've watched Neon Genesis Evangelion since that's where this phrase originates from (the ADV Dub of the series from 1997 to be exact) to the best of my knowledge. Thank you, Amanda Winn Lee (ADR Script Writer and Voice Actress for Rei Ayanami) for writing and saying this!
Rei: Woaagh! You're the jerk who was staring at my panties!
Asuka: Hey, what do you mean by that?! You're the one who was flashin' them y'know!
Rei: Oh and who are you and why are you defending him? Are you riding his Baloney Pony?
*shock envelopes the classroom*
Asuka: We're just really good childhood friends! You shut up!
Hikari: Be quiet you two! We're in a class, not a bar!
Misato: Hey, this is more entertaining than class! Go on, I want to see how this turns out.
The grindset is a contemporary ideology of self-exploitation disguised as strength, deeply tied to the aesthetics of the “sigma male” and to new digital forms of patriarchy. It promotes the idea that human worth depends on productivity, economic success, absolute emotional control, and the ability to work endlessly, turning vulnerability, rest, community, and tenderness into signs of weakness. Beneath its rhetoric of discipline and power often lies a profound inability to relate healthily to pain, fragility, and human interdependence.
“That’s the grindset, brother. While weak men sleep and complain, sigma males stay disciplined, work in silence, suppress emotions, and build power while everyone else wastes time chasing comfort.”