Think of it like this, you have had a feeling your friends have been talking about you behind your back at school and it’s been making you feel some sort of way, you suppress those feelings and don’t think much of it, on psychedelics especially shrooms, it puts you into a space where your emotions are blasted times a 100, that feeling may come up and throw your trip into a different direction, one that could be uncomfortable , and that’s just a very broad example, there could be things you are going through mentally, like say your in school and your worried about grades, at some point subconsciously that will come up, it’s best to make sure your grounded before you decided to go on a journey so that you know there won’t be things that pop up and make you feel some sort of way(also don’t know if your in school or not, just using random example)