Males can go off their food during the mating season and tend to get more restless at that time of year. It's not really a "personality" thing but it can make their behaviour awkward to deal with until you've experienced it for a year or two. However, you do get to understand their routine, so it won't be a big deal after a while. You'll have 15+ years to understand what's going on!
Surprisingly, husbandry can also play a part. All Corns can get snappy and irritable if they're kept too hot, so make sure that you factor in a good heat source, plus a thermostat to control it and a digital thermometer to monitor it. A Corn's safe maximum is below human core body temperature, so you'll be surprised at how cool they prefer things.
Older Corns (i.e. not hatchlings) tend to be more relaxed about being handled. Hatchlings are naturally jumpy as in the wild, everthing else would be trying to eat them. Sub-adults or adults are a little more confident in their dealings with people, so they might be a better bet as a "starter" Corn. Having said that, Corns of all ages usually settle down well with gentle and patient handling after an initial hands-off week when they first arrive.
Bear in mind that each Corn is an individual, with individual preferences and dislikes - just the same as cats or dogs. Personality can sometimes just be the luck of the draw, although the vast majority of Corns are perfectly happy to interact with people.