There's something massive about The Witness that won't reveal itself to most players until many many hours in, fyi. To say anything more is a spoiler.
This is a special game, and I strongly encourage everyone to truly let puzzles sit with them, rather than resorting to a walkthrough or wiki. I think most gamers (including me!) are willing to give a tricky puzzle an honest shot, but then if they're stumped, on to an IGN wiki or GameFAQS they go.
Please do not do that, with The Witness. It's an open world game - go mess with another part of the island. Come back after you've slept on it or a few days later. To do anything else is to deprive yourself of something really special. Just this once, really try to let the puzzles and let the game soak in and sit with you.
Think about it like this - you only get to play The Witness for the first time once. If you give in and look up puzzle solutions, you'll enjoy the game. It's very pretty, you'll feel smart at parts, etc. But if you resist doing that, and truly solve everything youself, you'll enjoy it on an entirely different level.
To put it another way - the puzzles are the game. Looking up solutions is akin to letting someone else beat a tough shooter level for you, or giving in to the kiddie star after failing a tough Mario stage enough times.
...and plus every time you look at a walkthrough you run the risk of having The Thing spoiled for you, which you do not want.