Are ideas spontaneous and instant or 'a part of a big process'?

An idea may appear to be spontaneous but this is a part of continuous though process that depends on material or physical experience and surroundings. That is why people belonging to different regions, religions and ethnic races think differently. 

Ideas already exist, deeply inherent within our soul. Based on our nature, state of mind and circumstances, and also when the time demands, we recall those ideas and bring them to the surface. If it is already matured and cultured at the time of inception itself, it blossoms out spontaneously as a beautiful quote or a mesmerizing verse. We call them a ‘spark’ or an ‘intuition’. And there are some ideas that we have to brood under the gentle warmth of our heart for a long period to develop into an amazing story or novel. Here the pain of creation and the contentment of the soul will be indefinable.

To me it's always like a bullet that hits me suddenly but I could seldom utilized it. It always came to me at a wrong time.

Ideas need not be a part of a big process. If they are part of a process, the idea that emerges is not spontaneous. Behind everyspontaneous idea there is "Intuition". It need not have any basis . The idea that comes out due to Intuition  look always spontaneous.

Writing poem can be spontaneous no doubt and I also agree

Ideas are exactly that, spontaneous and generated in that instant. If they were not spontaneous, then they would not be ideas but thoughts.

Ideas come from deep thoughts and deep understandings.

Generally ideas are spontaneous but they normally have a background to them because at some stage something would have made an impact and something else triggers it off ..It is the sub conscious that makes this happen. The power of our mind is immense and with proper direction we can achieve a lot..