On that same note, being in the military, I have taken an incredibly diverse selection of standardized tests to determine different aptitudes. Some I did great on, others I did not so well on. Let me give you an example. I took a test called the DLAB, or Defense Language Aptitude Battery, a test designed to measure your innate ability to learn a foreign language. The test basically consists of hearing and deciphering a made-up foreign language given a quick overview of the rules of grammar and syntax. I performed at about an average level. The ability to learn a language can be defined as "intelligence". Meanwhile, in tests like the LSAT I do much better, percentile wise. The tests that measure reading comprehension or logic tend to come much easier, probably because I have innate skill.
You have to take all the posted scores and GPAs with a grain of salt. For example, I'm not singling anyone out, but no one in my entire faculty of 1,800 students has a CGPA above 3.96. And, there are only two students who's above 3.9, that's 0.1%!
Intelligence and 'smartness' are two different things. Any idiot can be 'smart', but intelligence is a natural trait.
Standardized tests measure a certain kind of intelligence, probably one that's largely innate. It probably makes you good at accounting or finance. But it doesn't show you know how to work hard or have people skills.
FWIW, the Stanford-Binet IQ test I took at age 14, the AS*V*AB at 15, the NMSQT at 16, the SAT and ACT at 17, and the LSAT I took at age 39 all put me in roughly equivalent population percentiles, 98+%. From my point of view, they seem pretty consistent despite age, and I figure must be measuring approximately the same things.