The most important thing, you need to remember all countries visited and dates.
Bring all old and current passports.
Even for land crossings, make sure to list every trip over 24 hours.
If you can't remember, it's your job to reconstruct all dates. Things that may help with that:
- credit card charges that would show purchases overseas
- paper receipts for purchases while on trip
- phone location history
- email communications
- chat messages mentioning trip
- photos taken overseas
- rideshare trips if you took some overseas
- talk to friends / family / work colleagues who you visited overseas, they may remember dates