Collected from childhood until I sold my collection in the early 2000s to provide money for start-up business I was establishing, nice worldwide collection (the business later folded, now wish I hadn't sold the collection...ah the lessons of life!). Father passed away in 2009 and I
inherited his collections/dealer stock (he was a part-time dealer in the Thousand Islands region of New York) and now the stamp bug is biting again after a several-year hiatus.
Collect pretty much everything, can't focus on just one country or group of countries. Currently going through my father's dealer stock and collections (USA/Canada/Australia/Malaya-Singapore) as a starting base and then see what else catches my fancy. Generally collect pre-1919 used (and if possible with readable CDS, just something wonderfully romantic about seeing exactly where and when a stamp did its duty), mint thereafter (hinged until the mid-1950s for most countries, though my USA starts NH in 1935).
Just finished organizing the USA collection up to 1972 into a 64-page Lighthouse stock book. Wonderning how many more stockbooks will be needed to house the collection up to 2002 (and still debating if I want to continue beyond that...decisions decisions).