"People in their 30s, psychologically speaking, are going to a peak in their lifespan chart," psychotherapist and counselor Tati Silva told Bored Panda. "It is the beginning of our middle adulthood when we start to say 'goodbye' to our early adulthood, which for some can be challenging."

One study by a British social-networking site called Friends Reunited found out pretty much the same thing. 70% of respondents over the age of 40 thought they were not truly happy until they reached 33.

"The age of 33 is enough time to have shaken off childhood naiveté and the wild scheming of teenaged years without losing the energy and enthusiasm of youth," psychologist Donna Dawson commented on the findings.

Another study by insurer Aviva came to similar results. They asked more than 2,000 adults what they thought the best age was to be and the average came out as 35. While only those aged 45-54 picked that exact number, most groups chose somewhere in the 30s, except for 18-24-year-olds who thought it was 27 and those aged 65 and over who answered with 44.

But the age doesn't come without its fair share of doubts, too. "People start getting anxious about their future, questioning if they are in the right path," Silva explained. "There is an increase in anxiety and depression in the 30s as a result of looking back to the past and questioning the future. The high hopes and expectations we have when we're teens start to be challenged by reality and dreams are painfully crashed."

However, chances are, your personality won't change that much during this time. According to 20th-century Harvard psychologist William James, after age 30, a personality has “set like plaster.” Some studies back up this claim as well.

"Research about personality traits shows that personality doesn’t change for a long period of time over our lifespan," Silva explained. "There is a recognizable change from childhood to age 30, becoming more stable and gradual after that (Terracciano, Costa & McCrae, 2009). My experience working with clients across their lifespan shows that there are a better understanding of who they are and things they want to change. I observe a continuous personality development."

"30s can be seeing as a new beginning, which can bring anxiety but also lots of hopes, to reshape, restart, rethink," Silva concluded. "It can be an exciting time to review what you have done and where you want to go. Start a new book or continue the one you are already writing."

To put it simply, you're still probably going to be the same you after you hit the big 3-0. Just an upgraded version!