I did a bit of reading on the raw value applies in your case. From what I have found, the raw value ends up meaning completely different things depending on who made the drive. The utilities will "normalize" the raw value in different ways, to make it "easier" to read. For example, when looking at my hard drive for the spin retry count value, I have a raw value of 0 as well, but my normalized value is actually 100, which is the "best" with this program, and the threshold is 97, meaning if it goes below 97 I have reason to worry. However, it still means 0 times it's failed to spin on it's first time and needed to retry.
You asked why the value doesn't go up when it first spins up, it's because the value will only increase if it
fails to spin up and needs to retry it. The actual first spin up attempt is recorded in a different S.M.A.R.T (Self-Monitoring Analysis and Reporting Technology) value, which is what we're talking about (S.M.A.R.T values).
Anyways, enough with the history lesson and back to your primary concern: why does the raw value read 0 and the percentage read 45%? To be honest, I'm not sure. Different programs will report that raw value of 0 in different ways. For some reason the program you are using is interpreting it at 45%. I have never personally used a program that reports percentages so I can't compare. A good bet would be to look at the drive with a few other utilities and see if they still report a raw value of 0 (they should if nothing is wrong), and consider the "percentage", or normalized value irrelevant.
Now to my main point: If the raw value is reporting 0, it is reporting that 0 times it had needed to retry a spin after failing on the first spin up attempt. This value would take precedence and be considered the "right" value and to trust. I would consider the drive fine, but you can look at the drive status with different programs to be sure.
However, if you want to run drive-specific diagnostics as a final double check, you are going to need to figure out the manufacturer of your drive. You can either look in the BIOS and Google the random jumble of letters and numbers, use a drive utility and it should probably give the same serial number or it may even out right tell the manufacturer. Lastly you can power down the laptop, take out the battery, then take out the hard drive and look at the label on that. Manufacturers will include Western Digital, Seagate, Toshiba, Hitachi, etc. Google that specific companies diagnostic tools and run those. If they still don't report anything wrong, then I don't think you need to worry.
Sorry for the long read, but I wanted to be thorough. I don't know why a raw value of 0 is normalized in that program as a 45%, but if the raw value is still 0, I wouldn't worry about it.
Some good readings I came across:
http://www.easis.com/smart-value-interpretation.html
http://www.almico.com/sfarticle.php?id=2
http://www.ntfs.com/disk-monitor-smart-attributes.htm
http://www.z-a-recovery.com/man-smart.htm
http://harddrivemonitor.com/smart.html