Its also important to remember that as humans we tend to vastly over-estimate the incidence of relatively rare things. We tend to think that something happens based on how often we encounter it, without considering the total number of encounters.

4.5% is about 1 in 22. 8.2% is 1 in 12. Even accounting for the fact that most LGBT people are as private about their sexuality as straight people are, its often enough that you're likely to encounter LGBT people on a frequent basis.