Perhaps because most activities and entertainments are best enjoyed while sharing them with someone. Only a few distractions fair well solo for a social being.

Video games, videos, and creative crafts tend to do well, with only the creative bits accomplishing anything. So the question would be what can you do and within reason, what do you want to begin doing (that you would have patience for)? The last comment is that many things might easily require say 500 hours to become competent at, investing only 60 hours would then be a waste.