- Change of setting loosens pre-existing habits (compare working in an office to working from home)
- Being surrounded by people doing the same thing as you can be a great source of energy and determination (compare working in a hacker space to working in your garage)
- Having a teacher handy to clarify doubts is a great source of accountability and advice (compare learning from another programmer to teaching yourself to code)
- Depending on the retreat, most chores are taken care of for you so you can focus on meditating (compare being a student with a dining hall to studying while employed)
Often the metaphor used is that a retreat is a container, i.e. it makes it easy to slip into habits conducive to long and concentrated meditation sessions. Peers and environment matter, even for meditation.
I similarly attended these retreats and the community was profound. At every retreat I went to attendees participated in communal work, kitchen cleaning, food prep, compost rotation, temple cleaning. Nothing was a chore, not even silence, because you weren’t isolated. A big part of community was also the integration of monks, nuns and lay people (attendees). The kindness, acceptance and joy the “contemplatives” (monks and nuns) shared with attendees was really very special.
So, theoretically one could meditate alone at home during a weekend but…that’s an entirely different experience.
Short of attending a retreat, the next best thing is finding a Sangha locally and practicing together. Not every journey begins on a lonely road, some start walking slowly alongside others.
https://plumvillage.org/about/international-sangha-directory...
So, why can't you just do it? A solo retreat is not for everyone. People often need help or support to meet them where they are. Different personalities have different needs. A retreat can also be quite destabilizing and having someone to help in person to navigate the emotional territory or insights is valuable. Now, let's say that you think you can do it. In my opinion, you absolutely need a teacher for a longer retreat but for a shorter retreat (1 day, or _maybe_ 3-day) it is not entirely necessary. You end being your own worst enemy on a retreat. A friend of mine was doing practice for 10-12 hours a day without a teacher for 6 weeks and only eating a little bit of bread everyday. This is a bad idea. The mind plays some amazing tricks on you. So, if a solo attempt is done please have a teacher and have a lot of vital context around what you are doing otherwise you will practice wrongly.
I generally am a fan of the Nike, "just do it", but have found it can be significantly beneficial to be surrounded by those who do it better than you. Even if it's primarily a solo journey.