After spending years and years on my own, writing a PhD and looking after children, house, dog and cats, I am working in a team again. It is fantastic but it does bruise my private bubble almost hourly.
First of all, the idea that you have to know everything is superseded. Let alone that you do know anything. Having been out of practice for almost 15 years (apart from small conversions and bathrooms and the like), I notice that practice has evolved. There are many more consultants and the architect is much kinder to the client. When I worked in practice (it may have been the offices I worked in), we would never use reference images: that would mean that we were suggesting something that existed already. Now we use them all the time. This is much kinder to the client, who is not asked to take a leap of faith, but who is properly informed about what they can expect.
These may be issues that existed in practice before. There are two things that make it hard to return: first of all, to understand there has been a cultural shift form with work colleagues. Second it is hard to gauge what has changed and what has stayed the same. For example talks about structure and building processes have not changed as much as I thought. Whereas the admin side for organising files, drawings and their links have changed considerably. I find myself overconfident and capable one moment, to be utterly despairing the next.
I discussed this with a friend, a former editor at a well-known glossy magazine. She said she would never want to get back into her old work environment: everyone will be so much more on the ball, so much quicker. Solutions you would not think about for a minute now cost hours. She set up on her own. Taking her time.