@Pilot DAR: It may be fairly hard to load a Cessna wrong to get out of the envelope, but fairly easy done when taking passengers
Read carefully! What I said was:
Though it's generally fairly hard to mis load a 152 (unless you're piling cargo into the back), other types are easy to mis load, and unsafe to fly out of balance limits.
It's surprisingly easy to load most other Cessnas out of limits, and care must be taken! As a very new pilot, I actually misloaded a `172 with half tanks, one adult and two kids aboard! The fact that "she seems to fly okay" is by no means that the W&B is within limits, or acceptable. A wrong loading may show itself viciously (even in a 152) if you approach the stall. I have had to test modified Cessnas for ballast installations, and there's a lot more to getting a W&B right than "it seemed to fly okay..."