You need a plan because there will be moments you will get triggerd to buy. If you don't have planned out how to handle these situations, you will be screwed.
Without actively learning about personal finance, you won't achieve anything financially other than what the norm is. Again, the norm is a nightmare. It is bankruptcy in the worst case scenario and living paycheck to paycheck without fulfilling your dreams in best case scenario. That doesn't sound appealing, does it?