Because there's a real danger that you could learn something about yourself, a family member or a friend that you would rather not know. 

This may sound a little far-fetched but it's perfectly true. The problem with being able to read handwriting is that you can become privy to revelations about people that could prove embarrassing.

If you can read handwriting - and I mean really read handwriting, at some stage in your career, you will come across disclosures that will make you feel uncomfortable.

You see, with handwriting there's no bluffing. Handwriting analysis takes you right down to the foundations of personality so that you see the real person with no pretences.

It strips down all the facades that we carefully build up to hide our real selves from public view. And so it can come as something of a shock to see people the way they are warts and all. The face behind the Mask

In fact there are some people who go through a period of emotional adjustment when they first start their studies in handwriting analysis. They have to come to terms with the consequences of finding out rather more than they bargained for.

So you really have to be quite sure that you want to familiarize yourself with this technique. 

Of course there's a  plus side too because you can learn so much about human nature and get to understand so much more about the way people think and behave.

You learn to see their real motives. No matter what pretences they put up, you'll be able to see through them. You'll see through arrogance, insincerity and haughtiness on the one hand and lack of self-esteem, timidity and sensitivity on the other.

There's a lot more too; but suffice it to say that handwriting reveals more about character and personality than you can imagine. It's a powerful tool that should be used with discretion.