When I was young, Mazz and I despised each other. So much so that Ma took us to counselling. We saw a lovely lady named Peg. Something happened during those sessions. Mazz and I became best mates, a team, we'd laugh in Pegs face and tell her to "get on the clothes line" - we thought we were funny! The minute we walked out the door we were pulling each others hair, fighting over who got shotgun.
I took the counselling sessions I've had in my adult life a little more seriously. the main thing I've learnt is that you need to be constantly conscious of your thoughts.
I always assume. I'll always have doubts, but I'm now learning to acknowledge those thoughts and process them correctly.
It's all about being conscious.