This statement is deliberately full of multiple meanings, which is why it sounds a little odd. The writer has stretched the meanings a little. 'Pretreatment' and 'Condition' are alluding to beauty or hair treatments. Conditioning is a process that you do to hair after you have shampooed it. But these words can also be interpreted literally. Here 'condition', as Marty said, means 'prepare yourself', or 'get ready', and 'pretreatment' suggests preparations that you could make for yourself before something. Top runners 'condition' themselves prior to a particularly demanding race or event. You haven't given us the text that relates to what that 'something' is, but we can guess that it is some task or event that needs confidence.

Hazem -- this seems like a machine-translated sentence. "Pre-treatment preparation" really isn't natural English. You also wouldn't say 'with this fact' after this use of 'condition.' Having said that, this basically means 'prepare yourself.' Much like you condition yourself in a gym, or to run a marathon, you can condition yourself to hearing something or to doing certain things. Ex. I've become conditioned to hearing criticism from my trainer. Ex. Running a marathon requires a lot of conditioning. Hope this helps.