When I was younger I used to dread exams. All the way from the build up, the revision, the exam itself up until the moment you come out of the exam hall and realise you got completely different answers to all your friends...
However, the importance of obtaining Salesforce certifications, especially if you've just started your Salesforce journey, in my opinion is vital.
The reasons are pretty clear:
1) Employers want certified candidates. If you're not certified and you're going up against other candidates who are, there's a strong chance you would miss out on even securing an interview.
2) You will learn more from the studying and the exam itself.
3) Builds your reputation. It will show potential employers or current employers that you know your stuff, in turn, building their trust in your work.
4) More certifications = more opportunities = more money! The more time (and maybe money) you invest into gaining certifications, will inevitably lead to you growing as a Salesforce professional.
So, to summarise, try to forget about all of those bad memories that you have from school exams and get some certs under your belt... It will be worth it!
It is easy to miss the Salesforce forest because of the product trees. And the whole Salesforce universe is much greater than the sum of its individual parts.