You can also click on your own profile (top of page/"my profile")
Then it will show "Number of topics created" - which you can click on that highlighted number and they will be listed, you can then click on the topic of interest and read through the topic, answer it or whatever..
Or, you can click on the "Number of messages posted" number and do the same thing.
That way you can ALWAYS find any messages you have posted.
No excuses like, "I couldn't find the message/topic"