Advocating for yourself is a very valuable life skill. Using assertiveness to express what your needs are and you are not shy in anticipating that your needs should likely be met. This is great when it comes to striving to achieve things in life, or seeing that your needs are met in a relationship.
Could it ever backfire? Absolutely. Do you find yourself being alienated after you’ve shouted at someone whom you don’t agree with? After aggressively advocating for yourself, you may realize you’ve hurt the other party by being too aggressive, provocative or angry. By protecting yourself from being alienated, you could wind up alienating the other party.
This is why self advocacy must be tempered with self awareness and mindfulness. While advocating for yourself, introspect; check in with yourself every few moments to reflect on how much aggression you are putting out. Strive for politeness (a.k.a. not losing your temper) in your assertive communication and you will be happy and satisfied not just with the outcome but also with the way you achieved it. If you find yourself having these reactions with little provocation and have trouble controlling it, speak to your therapist or other mental health professional who can help you manage your reactions.