Why are some people devastated when they get an ASD diagnosis?

I have read a lot of accounts written by adults discussing their Autism Spectrum Disorder (ASD) diagnosis. In a lot of cases it seems that the person's world fell apart and it took them a long time to come to terms with the diagnosis.

I remember when I was handed the piece of paper with my ASD diagnosis and I think the councellor was expecting me to be quite emotional.

As it was - I was rather blase about the whole thing. It is not like other types of diagnosis (eg cancer) where you find out you have gone from being healthy to unhealthy in an instant, and now have a big battle on your hands. Instead it was quite helpful since it allowed me to put a name/label to why I always felt "different".

I am just curious if other people also reacted in a similar way to me?

I am also interested in hearing from those who found it a big shock to receive an autism diagnosis and found it hard to accept. I am just wondering why people react in this way? Perhaps it is because they felt under pressure in life to live a certain way? Luckily for me I have never had those pressures placed on me. My parents have always been quite "hands off" when it comes to telling me how to live.

Cheers!

Joe (diagnosis 7 months ago at the age of 37)