Being a fun person isn't a chore because I'm sure you already are very fun and interesting to be around. The thing that may create a hindrance for us and convince us to think otherwise is that we do not socially engage ourselves and aren't open about our views and thoughts. Now I'm not asking you to throw out your opinion uselessly and impose it on other people but sharing stories or your experiences can fuel life into certain conversations. 
Secondly, you want to be a good listener. If you're all about yourself and you're not willing or able to listen to the other person, sooner or later they're going to feel deflated in your presence. Therefore, be engaging where need be and express what you feel like but also let the other person do that.