It is so easy to get complacent and fall into the zone where you are accepting the status quo and allowing the Universe to manifest exactly what you have blindly accepted - status quo. Now mind you, if you are happy and life is beautiful and your status quo makes you feel joyful, energized and excited to wake up in the morning to see a new day of opportunities, then more power to you!
But most of us are in that zone where the 'lacks' in our lives rule and take up most of our energies and whether it is outright negative thinking or simply coping with the gap between our desires and our reality, our thoughts rule and maintain the current reality and manifestations are simply status quo - no change.
We are allowed to want, to desire, to wish for more all the time! Do it! Be thankful for what you have, and ask for more - nothing wrong or 'selfish' in the negative sense at all. Remember that everything you desire is there for the asking - so ask away!