Tolerance

So, about tolerance - what is with that current buzzword?
Let's have a look:

Let's begin with a dictionary definition from my fave dictionary.com

tol·er·ance   
[tol-er-uhns
–noun
1.a fair, objective, and permissive attitude toward those whose opinions, practices, race, religion, nationality, etc., differ from one's own; freedom from bigotry.
2.a fair, objective, and permissive attitude toward opinions and practices that differ from one's own.
3.interest in and concern for ideas, opinions, practices, etc., foreign to one's own; a liberal, undogmatic viewpoint.

So generally we can see that tolerance is a broad idea for people to be okay with other people who differ from ourselves in many and varied ways, such as culturally, opinionally, and practically.
This, I understand.

But then I have a thought:
If so many people consider themselves to be 'tolerant' towards others, then why do they have a big problem with another persons point of view which happens to be 'intolerant' towards another person or group.
Why do people get intolerant about intolerance?
Why are you pressing your view of tolerance upon other people? Is that not being intolerant?

I just feel it is a bit of an oxymoron that's all.
Any thoughts on tolerance??