I've never understood why people head off to the Spirit Temple before the Shadow Temple on their own. On their next playthroughs, maybe, (I've been considering an out-of-order OoT run myself) but the first time, I don't understand. People go to Kakariko a lot, since it's the main source of errands to run. Not only that, but after the Water Temple, Navi's hints point toward Kakariko Village, and people are more likely to randomly wander into Kakariko anyway. When that happens, the cutscene with the well plays, and Shiek teaches you the Nocturne of Shadow. Then, Navi's hints will tell you to go into the well, where you find the Lens of Truth, which are basically a necessity in the Shadow Temple. After that, Navi hints to you to play the Nocturne of Shadow and go into the Shadow Temple.
In addition to all of that, you need the Lens of Truth to get across the Haunted Wasteland, the way to the Spirit Temple. Also, in the adult part of the Spirit Temple, the Hover Boots are ALMOST required to obtain a Silver Rupee you need to collect. If you went into the well, got the Lens of Truth, and headed off for the Spirit Temple, every 15 minutes, it would be like this:
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
"Have you ever played the Nocturne of Shadow Shiek taught you?"
I fail to understand how video game instinct leads people to the Spirit Temple before the Shadow Temple.
Oh, and no, you aren't doing anything WRONG, I'm just curious what makes people do the Spirit Temple before the Shadow Temple the first time they play the game. Or the Water Temple before the Fire Temple for that matter.