I get inspired to do things because I have alot of hobbies and interests like writing and drawing, dance, gym, skating, musical instruments etc. There's creative inspiration, which may have nothing to do with competition or being 'better' that is often followed by a 'nagging' feeling if you don't actually realize your vision, some people simply see the potential in themselves and think it a waste not to try something, there's inspiration which is really more motivation that can just be all about crushing the competition. Alternatively, if there is a living example of someone else having achieved great things, jealous or not it gives you the go ahead that your goals and expectations are actually realistic.One can also feel inspired to do something (again, leaning towards motivation) when they see there is a market open, a problem, a need that requires addressing... and that is where Design as opposed to fine art comes in.
Would be more detailed but its 3 am and I didn't eat enough today.
Oh shit and I forgot, another motivator is simply taking pleasure in what you do rather than being fixated on the outcome. Sometimes I am bored and watch a blank screen in TextEdit and just try and MAKE inspiration happen because I know I like writing once I get started.
