Hello,

If you are having difficulty remembering tasks that you want to do when lucid, then I would probably say that you are not fully lucid
During a full lucid experience, you can think as clearly, and remember as clearly as when you are awake. The best way to gain complete lucidity is by grounding yourself. Once lucidity has been attained, integrate each of your senses to make yourself more in tune with the dream scape. Listen to each sound, touch different surfaces, smell the different smells, focus on objects at different distances. By doing this, you will really activate your dream body. You can also try cues such as "Increase lucidity". Say them aloud and they will work much like auto-suggestion. These are some of the best techniques that I have used over my years of lucid dreaming and I find that they never fail me!

I hope this helps.