Beating an adventure game is often an exercise not just in problem solving, but in building an intuition about how the game designer(s) wanted you to approach puzzles. Tuning into the vibe of the game world and understanding what interactions and approaches are likely to work and which won't. The most you can hope for is that the solutions have at least some logic to them. It's a bit like learning to solve cryptic crosswords, where you need to learn a hidden language to unlock the actual problems. This can be an enjoyable and rewarding experience, but it is definitely not the infinite freedom that the genre seems to offer up front, and I suspect for as many people who fell in love with these games, there were many who gave up in frustration at their paradoxical constrictiveness.