It's natural to aspire to something. People we meet tend to affect us in certain ways, occasionally becoming a symbol of those aspirations. Whilst that in itself might be a healthy thing, especially if they turn out to be a good mentor, just as often comparing yourself to someone else will make you miserable.
A tangible example is when you go to the gym and become discouraged by the dude next to you curling twice what you can. This type of thing goes on all through life whether it be at the gym, what's in your bank, what you look like (especially what you look like!) and the truth is, if it's happiness you're chasing, it's just about the most counter-productive thing you can do.
The only person worth comparing yourself to is the person you were when you woke up this morning.