For so many people I knew I doubt whether they might even come across this word in their life. Its really a hard time for me to listen to all their criticism that they just throw out on every single person they meet in their life but when it comes to appreciation that's it they would rather stay numb than to react. I don't think its that bad or tough job to appreciate someone truly. When you appreciate someone's work, you are indeed encouraging the person to strive better in his/her field. Likewise when you appreciate someone's valuable time with you, it better shows how much you enjoy the person's company. Appreciation of any kind indeed makes both of you happy.
I do believe when you criticize and force someone to do a work ends in a different land while when you encourage and appreciate the person's work will land somewhere that you would not even imagined the level of end result. The difference is huge. So before you point a finger at someone to dishearten their feelings, better understand that your other three fingers are pointing towards you!
Here I would like to include about a book I read long back and was the first one to come to my mind when I thought about the important quality of appreciation in life. Its "How to Win Friends and Influence People" by Dale Carnegie. If you get an opportunity please give it a try. I am sure you will love it and then there is lot more to learn from it. The basic quality which the author emphasis throughout the book is how to appreciate, encourage and influence people at work or at home.
And again I would like to add this too. Please don't work on anything expecting an appreciation from anyone in your life. Be sincere and give your heart to anything you do and I am sure you will deserve more in life.
Appreciate people for their good work and you will be remembered forever in their life. Pat someone's shoulder to see even their eyes could smile.