Do your research or take a chance.
Before a trip, do research on directions, transportation expenses, entrance fees (if any), operating hours, etc. If you don't or you only remember a place to visit while already on the road, take the chance.
I had left all the Batangas trip planning to my Batangueño friend. He did research on all the pertinent information, but only remembered Mabini Shrine when we were on the way to Lipa from Laurel. We decided to give Mabini Shrine a go, only to find out it was the day they close for the week (Monday). All we could do was press our face between the bars of the gate and project our inner Puss in Boots, but, of course, to no effect.
For more lessons from the road, please visit Go Learn.