I'm learning and like to splurge on bike tools. I've re wrapped handlebar tape, swapped out stems, changed chainrings to compact, grease speed play pedals, disassemble cup and cone hubs to service, true wheels on truing stand, disassemble cassette for deep cleaning. I've only serviced bottom bracket once and need experience with that. I've never re-routed cables, straightened rear derailleur hanger, adjusted speedplay cleats, or adjusted derailleurs' position on bike (only adjusted shifting), so I look forward to those.