ugh I just joined a PhD program, and I never felt any more stupid than I am right now..I joined the program right after college, and I also feel incompetent in comparison to other PhD students in my program bc they have master's + work experience... what should i do? did I make a mistake of joining the program at such young age?

We all feel the same, including them! No matter your prior experience, you all deserve to be there. You all passed the entrance interviews and a supervisor sees potential in you to succeed. What you have done before means nothing, you are starting over and you have just as right to be there as them.

You are suffering from impostor syndrome, and it is very common in PhD students. You can find a lot of help out there and on here to help. So don't feel alone

Just do something or say something with confidence and people will think you know what you are doing. It doesn't matter if you have no clue because a PhD is a training program were a uni is a safe space to fail. I know it is hard to contemplate but just doing stuff will help you get past this.

Echoing rewt's response.

I'm just about 1 year in. I've got a Masters and work experience behind me and I feel like I know absolutely nothing and that I'm surrounded by people who are younger and so much smarter than me. So yes, it's very normal to feel like that and even if you'd joined later, I can assure you that you'll still feel like that!

I try not to think about what others are doing and how far they've got in their studies and just to focus on my own thing. Different supervisors will have different methods, I know some who were getting their students to write review papers in their first few months while mine was reassuring me that it was ok to just be background reading. My advice is to just do what works for you and if your supervisor can help then don't be afraid to ask (for me we're going to be setting more writing type deadlines moving forward so I have dates to work to).

Thirding rewt.

I do have a Masters, loads of work experience (relevant and otherwise) and I still flailed like a gibbering idiot this time last year. Starting a PhD is so much different to taught research: you have no timetable, no given reading list and, depending on your supervisor, no set workload. As someone who needs structure and a bit of pressure to perform well, I really struggled with the sense that I was left - trusted - to get on with things in my own time. It was a prime environment for Impostor Syndrome to rear its head.

It is also hard trying not to compare yourself to others, even though it isn't a race and you are all doing completely separate pieces of work. One of my PhD colleagues is like the Duracell bunny and seems to be able to rap out 5000 words a day! The thing is, my area of research is on a relatively new and rapidly changing topic so I reminded myself that a lot of my lit review efforts now will be well out of date by the time I come to submit. Instead, anything I do now is useful for context but there's no point getting ahead of myself only to have to dismiss it all at a later date anyway.

Someone showed me this recently:

Have a look - hopefully it will ease your worries a little.

I got something better. Day 2 of my PhD, my supervisor gives me a huge spreadsheet of data and I was asked to help interpret it/ write the discussion part of the paper. I have no clue on the area and spend forever trying to get some conclusions.

After 3 months of feeling so stupid, my supervisor tells me that she doesn't understand the results either. And that none of the co-authors have any idea. So I spent 3 months thinking that this was a mundane thing and that I was problem. Talk about starting with an inferiority complex.

Wow that's really something. I think you win! I was in quite a dark place starting my PhD in terms of my ability to something like that would have finished me off!