Enlistment Polygraphs

I am well aware polygraphs are not to be discussed. But I am TERRIFIED of polygraphs, my dad was a FED, he brought me in to “take your kid to work day” and they had a polygraph for the kids to take, I volunteered and the polygraph examiner asked me my name, age, school, and then finally “did you brush your teeth this morning” I answered yes(truthfully) and I got told I was lying 🤣 ever since then polygraphs have terrified me. Here I am 10 years later at 19 wanting to join the army and terrified I’ll get discharged/ reclassed if I fail a polygraph. I am scared to ask my recruiter because when someone brings up polygraphs usually they’re hiding something. How common are polygraphs during your time in the Army(was looking at being a 15T)? Curious how many soldiers take them. I would appreciate any answers that are allowed. Thanks