There are 3-4 main things that aptitude does and is good at - 

a. Upgrading packages - `$ sudo aptitude safe-upgrade -y` 

b. Installing packages - `$ sudo aptitude install $PACKAGENAME` 

c. purging (removing package + configuration files - `$ sudo aptitude purge $PACKAGENAME` 

Now all of aptitude exploits are written in /var/log/aptitude and its revolving gunzipped archives 

 ┌─[shirish@debian] - [/var/log] - [10030]
 └─[$] cat apt 
 apache2/ apt/ aptitude aptitude.1.gz aptitude.2.gz aptitude.3.gz aptitude.4.gz aptitude.5.gz aptitude.6.gz

Now I know that the data I'm looking for is probably in those aptitude logs. How do I tell aptitude to only show those packages which I installed anew rather than those installed as part of bicycle, any ideas anybody ?