Argh. So close...
1.
Pay attention when you have the fleeting thought "full moon--check rising time" so that you can be prepared.
2. Prepare for full moon rises by learning
how to photograph the moon with the new DSLR.
3.
Remember that you had the fleeting thought "full moon--check rising time" early enough so that you can get to the beach on time for it (whether you are prepared or not).
4. Curse Murphy's Law that states the sky will be cloudless for moonrise when you
aren't prepared for it (and the corollary that it
will be cloudy when you
are).