A principle you drop when it gets inconvenient was a mood, not a principle.

Principles are cheap while they line up with what you wanted anyway. The moment holding one costs something and it quietly disappears, you learn it was a mood that happened to sound like a commitment. That is not cause for shame, only for honesty about which of your positions are load-bearing. Knowing the difference keeps you from being surprised by yourself later.

Take one commitment you have made and picture it turning genuinely inconvenient. Decide now whether you would keep it. If the answer is no, stop claiming it and put that energy into one you would hold.