Searching for user posts -- handle versus name in message text

[FUBARinSFO]

I wasn't able to find any of my posts using my handle 'FUBARinSFO'  (except the one post that used that handle to indicate I had edited the message text).

On the other hand, but searching 'zider' I was able to find most if not all my posts (because I generally sign my name).

Is this normal?  How do you search by handle?

-- Roy Zider