Yes, so often we're simply told that this character is the most brilliant person ever... but then they miss obvious things and simply jump to impossible conclusions or whatever.

Writing characters that are actually intelligent is really, really hard and I tend to remember the few characters that seem honestly clever that I really tend to remember those. I still remember my jaw dropping when L first told Kira he was coming after him in Death Note because of the clever way that was executed. Not to mention how both of those characters exhibited a very different sort of intelligence and you could follow their reasoning process most of the time.