Exactly Tel. I say don't waste time with silly mnemonics, visualise the circuit and the theory and understand why it's like it is. Look at a star connection - each line wire connects only to one phase of the load so the line current must equal the load current. Look at a delta connection - each load phase is slung between a pair of lines so the voltage it sees is the line-line voltage. Compare now the opposite cases, phase voltage in star and phase current in delta, and it will be obvious that these are not equal to the line voltage and current.
Memorising things by rote can get you through exam questions but only knowing their derivation will help understand the subject. When you have a full, fluent grasp, then it's OK to fall back on your remembered data because if you forget, you can derive it again from scratch if needed. E.g. (2.Π.f) is called pulsatance or angular frequency and given the symbol ω. For 50Hz its reciprocal is 0.003183 and I tap that number into my calculator without thought because I use it so often. I also know it for about ten other frequencies, but if forgotten, or even if I forget what pulsatance is, I can still work it out from an understanding of how a capacitor or inductor works.
