People collect by instinct or by irresistible desire. 

Stamp collecting gives you knowledge 
of the world, about past and future, geography and history, art and scientific research. 
It's a hobby with no limits.

On May 6th 1840, the first stamp was issued in England, the " Penny Black ". 
Since then, millions of stamps have been printed in the world - it's now up to you to get interested !