Meter readings help?

Basically for the same reason that you get different readings before and after meals, and at different times. Your blood circulates, your body generates and uses glucose which is also being circulated. And so you're never using the same drop of blood twice. Add to that the fact that your meter works within certain accuracy limits, and that particles of food, dirt, etc on your skin may "contaminate" your sample, and you're not going to be able to guarantee to duplicate any reading!

You actually got three reasonably close readings, so you can be fairly sure that is about where your current level was. You could also take an average of the four readings, and use that if it would make you happiuer?

However, for the most part you should be looking over time for patterns and trends in the readings you take, as these are what is going to tell you what's going on... So it's not worth getting yourself into a lather over single "odd" figures, unless they are very much unexpected, in which case wash your hands and try again. Then if the repeat reading is similar, you need to think about why - are you stressed , feeling ill, have you eaten something that is raising your glucose levels, etc.

Robbity

Might have had different amount of sweat residue on your hands, always wash them.
Apart from the above, it could be that x

As above and as above. Meters are +/- 15% accurate. Bg is dynamic so constantly changing. Contamination on hands or not very careful handling strips etc etc. Just take the one reading and go with it. Unless you think it's wildly out. Otherwise it drives you crazy and gives you sore pinkys .