Ok I'll bite.

If you show up and put your time in studying and doing everything you can on your end to show them you want to be there and are trainable, they will work with you, to a point, if you have some issues. If you show up and put in a half a**ed effort you will not make it through. Probably goes without saying that all other airlines are about the same.

If you are worried about how easy or hard 121 training is going to be, maybe re-evaluate if you are ready or not for it. Nothing wrong with that, but its better to realize that before you jump in head first.