[Davies]

It depends on the game and your mood at the moment.

A badly designed, illogical puzzle can force anyone to use a walkthrough. Sometimes even after reading the answer you still don't know why it's supposed to work!

If you're not in the mood to think very hard, and just want to get through the story, you'll be more likely to grab a walkthrough (and probably be playing an easier game anyway). Other times you'll want a harder challenge and feel like doing more work for yourself. This just depends on how you feel from day to day, depending on health, family, work, etc.

As Keregioz says, sometimes a game is just not entertaining enough to make you want to work at it, but you still want to get to the end. That's a good time to look at walkthroughs too.

There's not really any sort of measure for "how good you are" at adventure games. They're not like arcade games where you can point to a score. You probably have a feel for how much experience you have, and what sort of difficulty level you prefer. As long as you're enjoying yourself, that's all that matters.