Changing routines

Every how many months should I change my routine? This guy at the gym told me that I should switch routines every month and I don't think you should do that every month because that's bullshit, what do you guys think?

 

Well, if you want to get big you have to shock your body.
You shock your body by using different exercises, personally I change some exercises on weekly base

 

If you're new, stick to a routine that's already been proven to work and just add drop sets and super set

 

No. If your workout is working keep with it.

 

Okay and how long do you think should I stick to Coolcicada's PPL? I have been on full-body for 3 months and I started doing PPL since mid July.

 

Until you stop seeing results/get bored of it/priorities shift (emphasize different body parts etc)