Before the new forum site was introduced I could easily find a list of all my posts (which was helpful for looking back at old solutions). However now It seems a performance to search and find my old stuff (inbox and activity seem to have everyone else's activity). Out of interest, am I overlooking a button where all my old posts are listed?
The following silly roundabout way will give you (very close to) all your posts as far back as you wish:
1) Go to the Overview page of any forum and type a* in the Ask a Question box to search all posts containing at least one word beginning with a (except the short form of the indefinite article a), then click Search all results in the [Current forum] under Discussions, not under Answered Questions;
2) In Restrict Results to the left: Enter your name in the Author box and tick your avatar to have you selected, then click the cross in the box right below to change from from [Current forum] to Community... to include all forums;
3) At the bottom left: Change from Relevance to Last modified: newest first in the dropdown list.
You could use another search term in 1), such as I covering every mentioning of yourself, or t* covering the definite article and all other words starting with t, but a* will cover almost all sentences, and I believe it is the safest bet.