Marian - sometimes it just depends on the game, but mostly on how I'm feeling at the time. You see above that I did take a peek at the w/t the other day.
I just finished replaying Keepsake last week. There was one puzzle in the observatory that I spent hours and hours on and partially solved the puzzle but in the end I just got tired of it and looked at the w/t. Guess what. I spent all that time for NO reason. I was putting numbers in exact order in the puzzle but they only needed to be grouped, not exact. ARGH!!! Moral of the story: sometimes determination is over rated!