Ive turned into a noob at ripping bongs again!!!!

This Happened to me sort of. I could take huge rips and it wouldn't even phase me. About a few months later my friend brought over this beaker bottom which I was sure never had been cleaned in its entire life time of being a nice lil bong. All I have to say it was like smoking rubber bouncy balls. I coughed my fucking lungs out and so did every one else. So it might be from going to a smaller bong to a larger one. Dirty Bong. Bad Marijuana. Or your lungs repaired the damage from smoking previously and they don't want it to happen again so coughing is just natural reaction.