Guides
Practical guides to the problems the mygems apps were built for: big CSV files, mind maps, habits that stick. Written by the person who builds them.
- How to restart a habit after breaking itA missed day costs almost nothing; the response to it costs the habit. Here is how to tell resuming from restarting, and what actually broke.Read the guide
- How to turn a Markdown outline into a mind mapAny indented list is already a tree, so the conversion is a change of view. Here is how to write an outline that imports cleanly, and get one back out.Read the guide
- How to compare two CSV files and find what changeddiff compares lines, so a re-sorted export looks entirely rewritten. Here is how to compare by key instead: what is new, what is gone, what changed.Read the guide
- How long it actually takes to form a habitThe 21-day rule comes from a 1960 book about plastic surgery. The research says a median of 66 days, with a range of 18 to 254. The range is the useful part.Read the guide
- How to convert a CSV to PDFA CSV has no page and a PDF is nothing but pages, which is why columns fall off the edge. Here is how to decide what goes in before you convert.Read the guide
- How to use mind maps to studyBuilding a map helps; looking at one is re-reading. Here is how to make study maps you can test yourself against, and what to use flashcards for instead.Read the guide
- How to remove duplicate rows from a CSV fileMost duplicates are two records for one person rather than identical lines, and one of them is newer. Here is how to find them and keep the right one.Read the guide
- How to merge multiple CSV files into oneConcatenation matches columns by position, so one file with a different header order quietly ruins the result. Here is how to merge by name, and verify it.Read the guide
- Habit tracking without notifications: a quieter methodReminders stop working the moment you learn to swipe them away. Here is how to build habit tracking that runs on placement and review instead of alerts.Read the guide
- How to turn meeting notes into a mind mapLinear notes bury what a meeting actually produced: the decisions, the open questions, who owes what. Here is a repeatable way to restructure them into a map.Read the guide
- Free AI mind map generators, compared (2026 guide)Most free AI mind map tools cap you at three maps, watermark the export, or want an account first. Here is what each one actually gives away, and where it stops.Read the guide
- Why Excel crashes on large files, and what to do insteadNot responding, frozen on scroll, dead on save. The cause is usually memory, recalculation and formatting rather than the row count. Here is how to tell which one.Read the guide
- How to open a 1GB CSV file (2026 guide)A gigabyte is where most tools stop being honest about what they can do. Here is what opens a 1GB CSV, what it costs in RAM, and what quietly truncates.Read the guide
- How to run SQL queries on a CSV file without a database (2026 guide)You do not need Postgres to run a GROUP BY. Here is how to query a CSV in place with DuckDB, SQLite, q or your phone, and which one fits which situation.Read the guide
- How to open a large CSV file that Excel won't open (2026 guide)Excel stops at 1,048,576 rows, and sometimes truncates without telling you. Here is how to open, read and edit a huge CSV file on desktop, and on a phone.Read the guide
- How to fix a broken or malformed CSV fileEverything in one column, stray quotes, rows that split in half, mojibake in the names. Here is how to diagnose what is actually wrong with a CSV, and repair it.Read the guide
- How to convert a CSV to Excel on a phoneYou have a .csv on your phone and someone wants an .xlsx back. Here is how to convert it on iOS or Android, and how to avoid the ways the conversion mangles data.Read the guide
- CSV vs XLSX: which format to use, and whenCSV is a text file with commas in it. XLSX is a compressed application file. That difference decides everything: size, formulas, dates, and who can open it.Read the guide
- The best free ways to view a CSV file on Android (2026 guide)Most free Android CSV apps are ad-heavy, truncate large files, or are Google Sheets in disguise. Here is what each option actually does, and where each one breaks.Read the guide
- How to open a CSV file on iPhone and iPad (2026 guide)Tapping a CSV in Files or Mail shows a wall of raw text, or nothing at all. Here is why that happens on iOS, and every route to actually reading the file.Read the guide