some people loosing her motivation maybe he/she discourage her superior from work because he/she did not receive a bonus or increase her salary.
example of how to motivate a persons when working on a large project we had a short deadline but they offered such a large bonus to finish early we found the motivation to get it done.
Yeah, incentives really makes a worker work harder. If a company could offer such extra pay to each worker, then probably everyone will work hard. Aside from that, a shorter working hours and more over time pay.
With regards to OP, I think that's normal. It's not about the "spark" it's about maturity. When you are growing/aging, the more knowledge/wisdom you will have. You will also become realistic with everything, compared to children who thinks too much about impossible things like magic.