Forster won his second senior cap during a warm-up game against Honduras, though he failed to make an appearance at the tournament itself as the Three Lions went out at the group stage.
However, the 26-year-old is happy with the experience that he gained from being out in Brazil with the national side.
"It was a fantastic experience. It was great to be part of a World Cup in Brazil," the shot-stopper told Celtic TV.
"On a personal level it was good to be involved. I think I learned a lot. You spend a lot of time around people that you're not normally around."
Forster and his Celtic teammates return to action on July 15 when they travel to KR Reykjavik for a Champions League qualifier.